PT0E-1984

Portable Multi-Gas Monitor

RX-8500/RX-8700
Operating Manual(MED specification)(PT0-136)

Contents
1 Outline of the Product...................................................................................................................................... 4
Preface ............................................................................................................................................................ 4
Purpose of use ................................................................................................................................................ 4
Definition of DANGER, WARNING, CAUTION and NOTE ............................................................................ 5
Method of confirmation for Standards and Explosion proof specification ...................................................... 5
2. Important Notices on Safety ........................................................................................................................... 6
2-1. Danger cases........................................................................................................................................... 6
2-2. Warning cases ......................................................................................................................................... 8
2-3. Precautions .............................................................................................................................................. 9
2-4. Safety Information ................................................................................................................................. 11
3. Product Components .................................................................................................................................... 12
3-1. Main unit and standard accessories ...................................................................................................... 12
Main unit .................................................................................................................................................... 12
Accessories ............................................................................................................................................... 13
3-2. Names and functions for each part ....................................................................................................... 16<RX-8500 (with lithium ion battery unit BUL-8000(Z1))> ......................................................................... 16<RX-8700 (with lithium ion battery unit BUL-8000)> ................................................................................ 19
4. How to Use ................................................................................................................................................... 23
4-1. Before using the gas monitor ................................................................................................................ 23
4-2. Preparation for start-up ......................................................................................................................... 23
4-2-1. Charging the lithium ion battery unit (BUL-8000(Z1)) .................................................................... 24
4-2-2. Detaching and attaching the battery unit........................................................................................ 25
4-2-3. Connecting the gas sampling probe and gas sampling hoses ...................................................... 26
4-3. How to start the gas monitor ................................................................................................................. 28
4-3-1. Power-on ........................................................................................................................................ 28
4-3-2. Switching the hydrogen sulfide measuring mode range on RX-8700 ............................................ 30
4-4. Basic operating procedures................................................................................................................... 31
4-4-1. RX-8500 basic operating procedures ............................................................................................. 31
4-4-2. RX-8700 basic operating procedures ............................................................................................. 32
4-5. Measurement ......................................................................................................................................... 33
4-5-1. Gas concentration measurement ................................................................................................... 33
4-5-2. Range switching point .................................................................................................................... 35
4-6. Air calibration ......................................................................................................................................... 36
4-6-1. Attaching the CO2 removal filter (RX-8500) ................................................................................... 36
4-6-2. Air calibration procedure ................................................................................................................. 37
4-7. Manual memory ..................................................................................................................................... 40
4-8. Stopping the pump (PUMP OFF mode) ................................................................................................ 41
4-9. Power-off ............................................................................................................................................... 42
5. Display/setting Mode .................................................................................................................................... 43
5-1. Display/setting mode ............................................................................................................................. 43
5-2. PEAK display/clear ................................................................................................................................ 45
5-3. Full scale/alarm setpoint display/gas alarm test (optional function) ..................................................... 46
5-4. Station ID display................................................................................................................................... 47
5-5. Log data display .................................................................................................................................... 48
6. User mode .................................................................................................................................................... 49
6-1. Displayng user mode ............................................................................................................................. 49
6-2. ................................................................................................................................................................ 51
Date and time setting .................................................................................................................................... 51
6-3. ROM/SUM display ................................................................................................................................. 51
6-4. Suppression setting: ON/OFF ............................................................................................................... 52
6-5. PEAK clear setting: ON/OFF ................................................................................................................. 53
6-6. Gas calibration function setting: ON/OFF ............................................................................................. 53
6-7. Station ID display setting: ON/OFF ....................................................................................................... 54
7. Alarm Function.............................................................................................................................................. 55
Gas alarm activation ..................................................................................................................................... 55
Fault alarm activation .................................................................................................................................... 56
8. Maintenace ................................................................................................................................................... 58
8-1. Maintenance intervals and items ........................................................................................................... 58
About maintenance services ..................................................................................................................... 59
8-2. Span adjustment .................................................................................................................................... 60-2-

8-2-1. Preparation ..................................................................................................................................... 60
8-2-2. How to connect ............................................................................................................................... 60
8-2-3. Span adjustment procedure ........................................................................................................... 61
8-3. How to clean .......................................................................................................................................... 65
8-4. Parts replacement ................................................................................................................................. 66
8-4-1. Sensor replacement ....................................................................................................................... 66
8-4-2. Replacement procedure for gas sampling probe dust filter ........................................................... 66
8-4-3. Replacement procedure for filter tube dust filter ............................................................................ 67
8-4-4. Replacement procedure for filter tube absorbent cotton ................................................................ 67
8-4-5. Replacement of regular replacement parts .................................................................................... 68
9. Storage and disposal .................................................................................................................................... 69
9-1. Procedures to store the gas monitor or leave it for a long time ......................................................... 69
9-2. Procedures to use the gas monitor again ............................................................................................. 69
9-3. Disposal of products .............................................................................................................................. 70
10. Troubleshooting .......................................................................................................................................... 71
10-1. Abnormalities on unit ........................................................................................................................... 71
10-2. Abnormalities of readings .................................................................................................................... 73
11. Product specifications ................................................................................................................................. 74
11-1. RX-8500 specifications ........................................................................................................................ 74
11-1-1. List of RX-8500 specifications ...................................................................................................... 74
11-1-2. RX-8500 standard accessories .................................................................................................... 76
11-2. RX-8700 specifications ........................................................................................................................ 77
11-2-1. List of RX-8700 specifications ...................................................................................................... 77
11-2-2. RX-8700 standard accessories .................................................................................................... 78
11-3. List of optional items ............................................................................................................................ 79
12. Appendix ..................................................................................................................................................... 80
12-1. Definition of terms................................................................................................................................ 80
12-2. Calibration history/various trend/event history functions .................................................................... 80
Revision or Abolition History ......................................................................................................................... 82-3-

1 Outline of the ProductPreface11Outline of the ProductPrefaceThank you for choosing our portable multi-gas monitor RX-8500/RX-8700 (MED specification)(hereinafter referred to as "gas monitor"). Please check that the model number of the product you
purchased is included in the specifications on this manual.
The product should be used only by fully-trained personnel.
Maintenance procedures described in this manual should be performed only by fully-trained
personnel. Any maintenance procedure not described in this manual must be performed by Riken
Keiki or our certified service engineers. Please contact Riken Keiki.
This manual describes how to use the product and provides product specifications. Make sure you
have read and fully understood the contents of this manual before using the product. This applies
both to first-time users and those who have previously used the product.
Keep this manual in a safe place for future reference.
The contents of this manual are subject to change without notice to allow product improvements. Any
duplication or reproduction of this manual without permission is prohibited, whether in whole or inpart.
In addition to this manual, manuals are also provided for optional products (sold separately). Refer tothe following manuals along with this manual when using optional products (sold separately):1) SW-RX-8500/8700 Pump unit Operating Manual (PT0E-137)
Regardless of the warranty period, Riken Keiki does not accept any liability for accidents or damage
resulting from use of the product.
Be sure to read the warranty policy set forth on the warranty.

Purpose of use
This product is a portable gas monitor capable of measuring multiple gases alone, which is requiredin LNG carriers or oil tankers. Measurable gases and ranges are shown below.
<RX-8500>
Measuring gas
Combustible gas (CH4)
Oxygen (O2)
Carbon monoxide (CO)Carbon dioxide (CO2)

Measuring range <Service range>
0 - 100.0% LEL/4.5 - 100.0 vol%0 - 25.0% <25.1 - 40.0%>
0 - 1000 ppm
0 - 20.0 vol%-4-

1 Outline of the ProductDefinition of DANGER, WARNING, CAUTION and NOTE

<RX-8700>
Measuring gas
Combustible gas (HC)*Oxygen (O2)

Measuring range <Service range>
0 - 100.0% LEL/1.5 - 100.0 vol%0 - 25.0% <25.1 - 40.0%>

Hydrogensulfide (H2S)

0 - 30.0 ppm <30.5 - 100.0 ppm>
0 - 1000 ppm[Low concentration][High concentration]* HC: Isobutane converted
RX-8500 is capable of measuring CH4 (methane) as combustible gas, whereas RX-8700 is capableof measuring general combustible gases HC (isobutane converted).
Note that measurement results of the gas monitor are not intended to guarantee life or safety in any
way.
Check the specifications before use and conduct gas measurement properly in accordance withpurposes.
In addition to this operating manual, an operating manual for the data logger management program(option) is available for the gas monitor. Please contact RIKEN KEIKI if it is needed.

Definition of DANGER, WARNING, CAUTION and NOTE
Throughout this manual, the following indications are used to ensure safe and effective work.

DANGER

This message indicates that improper handling may cause serious
damage on life, health or assets.

WARNING

This message indicates that improper handling may cause serious
damage on health or assets.

CAUTION

This message indicates that improper handling may cause minor
damage on health or assets.

NOTE

This message indicates advice on handling.

Method of confirmation for Standards and Explosion
proof specification
This instrument has some specification depends on standard and explosion proof certificate. Pleaseconfirm the detector specification before using. Please refer Declaration of Conformity that is at theend of this manual if you have CE/UKCA marking type. You can confirm instrument specification to
see name plate as follows.
ATEX/IECEx/UKEX certificate
Ex marking
CE marking
UKCA marking
MED marking

Type name plate-5-2. Important Notices on Safety

2-1. Danger cases

22.

Important Notices on
SafetyTo maintain the performance and use the gas monitor safely, observe the following instructions of
DANGER, WARNING and CAUTION.

2-1. Danger cases
DANGER
About explosion-proof
 Do not modify or change the circuit, structure, etc.
 When using the gas monitor in a hazardous area, take the following countermeasures forpreventing dangers resulting from electrostatic charges.
(1) Wear anti-static clothes and conductive shoes (anti-static work shoes).
(2) For indoor use, use the gas monitor while standing on a conductive work floor (with aleakage resistance of 10 MΩ or less).
 [RX-8500, RX-8700] When measuring the oxygen concentration, do not measure anything but
a mixture of air and combustible gases or vapors and toxic gases.
 [RX-8500, RX-8700] Connect lithium ion battery unit BUL-8000(Z1)(TC21188).
 [BUL-8000(Z1)] Connect either RX-8500 or RX-8700(TC21186) unit.
 [BUL-8000(Z1)] Replace the battery unit in a safe place.
 [BUL-8000(Z1)] Charge the battery unit using the dedicated AC adapter in a safe place.
 [BUL-8000(Z1)] Charge the battery unit at ambient temperatures between 0 to 40ºC.
 The specifications of RX-8500 and RX-8700 are as follows:
Pump circuit: Allowable voltage of 4.95 V, allowable current of 1.12 A andallowable power of 1138 mW
Infrared detection circuit : Allowable voltage of 4.95 V, allowable current of 0.834 A andallowable power of 853 mW
Buzzer circuit: Allowable voltage of 4.95 V, allowable current of 0.431 A andallowable power of 441 mW
Main circuit: Allowable voltage of 4.95 V, allowable current of 0.717 A andallowable power of 733 mW
Backup circuit: 3.0 VDC, 10 µA
Ambient temperature: -20 - +50ºC-6-

2. Important Notices on Safety

2-1. Danger cases

DANGER
About explosion-proof The specifications of BUL-8000(Z1) are as follows:
Pump circuit: Maximum voltage of 4.25 V, maximum current of 1.12 A andmaximum power of 901 mW
Infrared detection circuit : Maximum voltage of 4.25 V, maximum current of 0.768 A andmaximum power of 618 mW
Buzzer circuit: Maximum voltage of 4.25 V, maximum current of 0.410 A andmaximum power of 330 mW
Main circuit: Maximum voltage of 4.25 V, maximum current of 0.653 A andmaximum power of 526 mW
Battery charging contact : Allowable voltage of 250 VAC, 50/60 Hz
Ambient temperature: -20 - +50ºC
 Make sure that the product model on the nameplate is correct.
Inappropriate combinations of models deviate from the range of explosion-proof certification.
 The nameplate shows the followings as well as the product model.
Product model : Main unit: RX-8500, 8700
Lithium ion battery unit: BUL-8000(Z1)Explosion proof class : 【RX-8500,8700】Ex ia IIC T4X【BUL-8000(Z1)】 Ex ia IIC T4
Ambient temperature : -20 to 50ºC
Charging terminal rating : 【BUL-8000(Z1)】Allowable voltage AC250V 50/60Hz
Warnings : 【BUL-8000(Z1)】
Inhibit to take off battery unit in non-hazardous area.
 Manufacturer : RIKEN KEIKI Co., Ltd.
 IP protection class: IP20
About use While conducting measurement in a manhole orconfined space, do not lean over or look into the
manhole or confined space. It may lead to dangers
because oxygen-deficient air or other gases may blowout.
 Oxygen-deficient air or other gases may bedischarged from the gas exhausting outlet (GAS
OUT). Never inhale the air or gases.
 High-concentration (100% LEL or higher) gases may
be discharged. Never use fire near it.

-7-

Name plate

Name plate2. Important Notices on Safety

2-2. Warning cases

2-2. Warning cases
WARNING
Sampling point pressure The concentration meter is designed to draw gases under the atmospheric pressure. If
excessive pressure is applied to the gas inlet (GAS IN) and outlet (GAS OUT) of the gas
monitor, measured gases may leak out from its inside and may cause dangerous conditions.
Be sure that excessive pressure is not applied to them while used.
 Do not connect the gas sampling hose directly to a location with a pressure higher than theatmospheric pressure. The internal piping system may be damaged.
Handling of sensor
 Do not disassemble the carbon monoxide, hydrogen sulfide or oxygen sensor inside the gas
monitor because it contains electrolyte. Electrolyte may cause severe skin burns if it contacts
skin, while it may cause blindness if its contacts eyes.
If electrolyte is adhered on your clothes, that part on your clothes is discolored or its material
is decomposed. If contact occurs, rinse the area immediately with a large quantity of water.
Air calibration in atmosphere When air calibration is performed in the atmosphere, check the atmosphere for freshness
before beginning it. If interference gases exist, air calibration cannot be performed properly,
thus causing erroneous measurement and leading to dangers when the gas leaks.
Battery level check Before use, check that there remains sufficient battery power. When the gas monitor is used
for the first time or is not used for a long period, the batteries may be exhausted. Replacethem with new ones before use.
 If a low battery voltage alarm is triggered, gas measurement cannot be conducted. If the alarmis triggered during use, turn off the power and promptly replace the batteries in a safe area.
Others Do not throw the gas monitor into fire.
 Do not wash the gas monitor in a washing machine or ultrasonic cleaner.
 Do not block the buzzer sound opening. No alarm sound can be heard.
 Do not remove batteries while the power is on.
 Do not vibrate or give a shock to the gas monitor by, for example, relocating the gas monitor
with an optional water trap attached. The gas inlet (GAS IN) may be damaged.

-8-

2. Important Notices on Safety

2-3. Precautions

2-3. Precautions
CAUTION
Do not use the gas monitor in a place where it is exposed to oil, chemicals, etc. Do notsubmerge the gas monitor under water on purpose.
 Do not use in a place where the gas monitor is exposed to liquids such as oil and chemicals.
 The gas monitor is not water-pressure-resistant. Avoid using it in a place where a high waterpressure is applied to it (under a faucet, shower, rainfall, etc.) or submerging it under water fora long time. Note that the gas monitor is water-proof only in fresh water and running water,and not in hot water, salt water, detergent, chemicals, human sweat, etc.
 The gas inlet (GAS IN) and outlet (GAS OUT) are not water-proof. Be careful not to let watersuch as rainwater get into these parts. Because this may cause trouble and gas cannot bemeasured.
 Do not place the gas monitor where water or dirt gets accumulated. The gas monitor placed atsuch a location may malfunction due to water or dirt that gets into the buzzer sound opening,gas inlet (GAS IN), etc.
 Note that drawing in dirty water, dust, metallic powder, etc. will significantly deteriorate thesensor sensitivities. Be careful when the gas monitor is used in an environment where theseelements exist.
 The IP degrees of protection do not indicate whether the device detects a gas during or after it
was exposed to the relevant ambient conditions. The calibration and correct functioning of thedevice must be checked in the event of dust deposits or immersion/water spray.
Do not use the gas monitor in a place where the temperature drops below -20ºC or rises over
50ºC.
 The operating temperature of the gas monitor is -20 to +50ºC. Do not use the gas monitor at
higher temperatures, humidities and pressures or at lower temperatures than the operating
range.
 Avoid long-term use of the gas monitor in a place where it is exposed to direct sunlight.
 Do not store the gas monitor in a sun-heated car.
Observe the operating restrictions to prevent condensation inside the gas monitor or gas
sampling hose.
 Condensation formed inside the gas monitor or gas sampling hose causes clogging or gas
adsorption, which may disturb accurate gas measurement. Thus, condensation must be
avoided. In addition to the installation environment, carefully monitor the temperature/humidityof the sampling point to prevent condensation inside the gas monitor. Please observe theoperating restrictions.
Do not use a transceiver near the gas monitor.
 Radio wave from a transceiver or the like near the gas monitor may disturb the readings. If atransceiver or other radio wave transmitting device is used, it must be used in a place awayfrom the gas monitor where it disturbs nothing.
 Do not use the gas monitor near a device that emits strong electromagnetic waves (highfrequency or high-voltage devices).
Verify that the pump driving indicator is rotating before using the gas monitor
 If the pump driving indicator is not rotating, gas measurement cannot be performed properly.
Check whether the flow rate is lost.
Never fail to perform a daily maintenance before use.
 Before each day’s usage sensitivity must be tested on a known concentration of the gas to be
detected.
Never fail to perform a regular maintenance.
 The gas monitor is a safety unit. Never fail to perform regular maintenance. Continuing to use
the gas monitor without performing maintenance will compromise the sensitivity of the sensor,
thus resulting in inaccurate gas measurement.

-9-2. Important Notices on Safety

2-3. Precautions

CAUTION
Others Pressing buttons unnecessarily may change the settings, preventing alarms from activatingcorrectly. Operate the gas monitor using only the procedures described in this operating
manual.
 Do not drop or give shock to the gas monitor. The accuracy of the gas monitor may be
deteriorated. Recheck calibration if the product is subjected to physical shock.
 Do not use the gas monitor while charging it.
 Whereas the gas monitor can measure combustible gases, carbon monoxide, carbon dioxide,hydrogen sulfide and oxygen, the measurement environment may include gases that have
harmful effects on the sensors of this unit.
 When measuring concentrations of oxygen in inert gases for a long time, the carbon dioxide
concentration in the air must be 15 vol% or less. When the gas monitor is used in the inert gas
with a carbon dioxide concentration higher than 15 vol%, perform measurement in as shorttime as possible.
 Do not use the gas monitor in a place with high oxygen concentration for a long time. The
oxygen sensor life may be shortened. Also, if the oxygen concentration is measured for a longtime in hydrogen sulfide with a concentration exceeding 6000 ppm, the indicated value may
decrease. Similarly, shorten the measurement time as much as possible.
 Do not jab the buzzer sound opening with a sharp-pointed item. The gas monitor may
malfunction or get damaged, allowing foreign matter, etc. to get inside.
 Do not remove the panel sheet on the LCD display. The dust-proof performance will be
deteriorated.
 Do not affix a label or the like on the infrared port. Infrared communications can no longer be
conducted.
Replacement of batteries
 Turn off the power of the gas monitor before replacing the batteries.
 Replace all of the three batteries with new ones at one time.
 The explosion-proof standard for the gas monitor requires the use of TOSHIBA dry batteries(only when the dry battery unit is used). Use three AA alkaline batteries (LR6) produced by
TOSHIBA CORPORATION to use the gas monitor as an explosion-proof unit.
 Pay attention to the polarities of the batteries.
Usage In a low-temperature environment, the operating time is shortened due to the battery
performance property.
 At low temperatures, the responses of the LCD display may slow down.
 Perform air calibration under pressure and temperature/humidity conditions close to those in
the operating environment and in fresh air.
 Perform air calibration after the reading is stabilized.
 If there is a sudden temperature change of 15ºC or more between the storage and operational
locations, turn on the power of the gas monitor, let it stand for about 10 minutes in a similar
environment to the operational location, and perform air calibration in fresh air before using it.
 When cleaning the gas monitor, do not splash water over it or use organic solvents such as
alcohol and benzene on it. The surface of the gas monitor may be discolored or damaged.
 If the gas monitor is not used for a long time, turn on the power at least once every six months
and check that the pump draws in air (about three minutes). The gas monitor, when not
activated for a long time, may cease to work because of hardening of the grease in the pump
motor.
 If the gas monitor is not used for a long time, store it after removing the batteries. Battery
leaks may result in fire, injury, etc.
 When using the gas monitor after long-term storage, never fail to perform air calibration. For
information on readjustment including air calibration, please contact RIKEN KEIKI.

- 10 -

2. Important Notices on Safety

2-4. Safety Information

2-4. Safety Information
The Portable Gas Detector Model RX-8500/8700 is a gas monitors designed to provide continuous exposure
monitoring of combustible gas, Oxygen (O2), toxic gas such as carbon monoxide (CO), Carbon
Dioxide(CO2), and hydrogen sulfide (H2S) in hazardous environments. The gas sampling is suctioned bybuild-in micro pump.
The battery can be selected either Li-ion battery or alkaline dry battery.
Li-ion battery unit is called BUL-8000(Z1).
The battery unit structured even the end user is possible to replace.
Specification for safety
・Ex ia IIC T4 Ga

・

II 1 G Ex ia IIC T4 Ga

・Ambient temperature range for use ： -20°C to +50°C
・Ambient temperature range during battery charging ： 0°C to +40°C
Electrical data
・Power supply of Li-ion battery unit : BUL-8000(Z1)
Two parallel connected Li-ion cells used in battery pack BP-8000 are from type Maxell
INR18650PB1 or SDI INR18650-15M or SONY US18650VT3.
Um=250V..
Certificate numbers
・IECEx Certificate number ： IECEx PRE 15.0012
・ATEX Certificate number ： Presafe 15 ATEX6173X
・UK Type Examination Certificate : DNV 22 UKEX 25918X
List of standards
・IEC 60079-0：2017
・EN IEC 60079-0:2018
・BS EN IEC 60079-0:2018
・IEC 60079-11：2011
・EN60079-11:2012
・BS EN 60079-11:2012
Specific conditions of “X”-mark:Regarding ATEX specification, the measuring function according to Annex II paragraph 1. 5. 5 of
the Directive is not covered by this EU-type examination.
It shall comply with the requirements from the relevant European harmonized standards which
provide guidance on the performance of gas detection equipment and safety devices.
The measuring function according to schedule 1, paragraph 24 of the Regulation is not coveredin this UK-type examination. It shall comply with the requirements from the relevant UK
Designated Standards which provide guidance on the performance of gas detection equipment.
WARNING
・DO NOT CHARGE IN HAZARDOUS LOCATION.
・DO NOT CHARGE IT EXCEPT BY GENUINE CHARGER.
・DO NOT REPLACE BATTERY UNIT IN HAZARDOUS LOCATION.
・DO NOT ATTEMPT TO DISASSEMBLE OR ALTER THE INSTRUMENT.
INST. No. 0 0 0 0 0 0 0 0 0 0 0
AB C
DE
A: Manufacturing year (0-9)
B: Manufacturing month (1-9,XYZ for Oct.-Dec.)
C: Manufacturing lot
D: Serial number
E: Code of factory

Phone
Fax
E-mailWeb site: +81-3-3966-1113: +81-3-3558-9110 GIII
: intdept@rikenkeiki.co.jp: https://www.rikenkeiki.co.jp- 11 -

3. Product Components

3-1. Main unit and standard accessories

3
3.

Product Components

3-1. Main unit and standard accessories
Unpack and check the main unit and accessories.
If any part is missing, contact RIKEN KEIKI.

Main unit
See "Names and functions for each part" (P. 16) for names and functions of each part of the gas monitor
and LCD display.

<RX-8500 main unit><RX-8700 main unit>- 12 -

3. Product Components

3-1. Main unit and standard accessories

Accessories
Lithium ion battery
unit (BUL-8000): 1 pcAC adapter forcharging: 1 pcFilter tube andrelay tube: 1 pc

Filter tube andrelay tube: 1 pc

Absorbing tube fixing
belt: 2 pcs

Shoulder strap: 1 pcCO2 removal filter (CF283): 1 pc
(RX-8500 only)

Zero filter fixing belt
: 1 pc (RX-8500 only)

Product warranty
Operating manual- 13 -

3. Product Components

3-1. Main unit and standard accessories

DANGER
About explosion-proof
 Do not modify or change the circuit, structure, etc.
 When using the gas monitor in a hazardous area, take the following countermeasures forpreventing dangers resulting from electrostatic charges.
(1) Wear anti-static clothes and conductive shoes (anti-static work shoes).
(2) For indoor use, use the gas monitor while standing on a conductive work floor (with aleakage resistance of 10 MΩ or less).
 [RX-8500, RX-8700] When measuring the oxygen concentration, do not measure anything but
a mixture of air and combustible gases or vapors and toxic gases.
 [RX-8500, RX-8700] Connect lithium ion battery unit BUL-8000(Z1)(TC21188).
 [BUL-8000(Z1)] Connect either RX-8500 or RX-8700(TC21186) unit.
 [BUL-8000(Z1)] Replace the battery unit in a safe place.
 [BUL-8000(Z1)] Charge the battery unit using the dedicated AC adapter in a safe place.
 [BUL-8000(Z1)] Charge the battery unit at ambient temperatures between 0 to 40ºC.
 The specifications of RX-8500 and RX-8700 are as follows:
Pump circuit: Allowable voltage of 4.95 V, allowable current of 1.12 A and
allowable power of 1138 mW
Infrared detection circuit : Allowable voltage of 4.95 V, allowable current of 0.834 A andallowable power of 853 mW
Buzzer circuit: Allowable voltage of 4.95 V, allowable current of 0.431 A andallowable power of 441 mW
Main circuit: Allowable voltage of 4.95 V, allowable current of 0.717 A andallowable power of 733 mW
Backup circuit: 3.0 VDC, 10 µA
Ambient temperature: -20 - +50ºC
 The specifications of BUL-8000(Z1) are as follows:
Pump circuit: Maximum voltage of 4.25 V, maximum current of 1.12 A andmaximum power of 901 mW
Infrared detection circuit : Maximum voltage of 4.25 V, maximum current of 0.768 A andmaximum power of 618 mW
Buzzer circuit: Maximum voltage of 4.25 V, maximum current of 0.410 A andmaximum power of 330 mW
Main circuit: Maximum voltage of 4.25 V, maximum current of 0.653 A andmaximum power of 526 mW
Battery charging contact : Maximum voltage of 250 VAC, 50/60 Hz
Ambient temperature: -20 - +50ºC- 14 -

3. Product Components

3-1. Main unit and standard accessories

DANGER Make sure that the product model on the nameplate is correct.
Inappropriate combinations of models deviate from the range of explosion-proof certification.
 The nameplate shows the followings as well as the product model.
Product model : Main unit: RX-8500, 8700
Lithium ion battery unit: BUL-8000(Z1)Explosion proof class : 【RX-8500,8700】Ex ia IIC T4X【BUL-8000(Z1)】 Ex ia IIC T4
Ambient temperature : -20 to 50ºC
Charging terminal rating : 【BUL-8000(Z1)】Allowable voltage AC250V 50/60Hz
Warnings : 【BUL-8000(Z1)】
Inhibit to take off battery unit in non-hazardous area.
 Manufacturer : RIKEN KEIKI Co., Ltd.
 IP protection class: IP20

NOTE
Connect either the dry battery unit BUD-8000(Z) or
lithium ion battery unit BUL-8000(Z1).
Check the model of the battery unit with the nameplateaffixed to the unit.
A nameplate indicating a compatible model is affixed tothe battery unit to avoid using the gas monitor in
combination with a wrong unit.
Check this information and use a correct combination.

(Top view of battery unit)

Nameplate(Side view of battery unit)- 15 -

3. Product Components

3-2. Names and functions for each part3-2. Names and functions for each part
This section describes names and functions of main unit and battery unit parts and LCD display.

<RX-8500 (with lithium ion battery unit BUL-8000(Z1))><Main Unit>

Name
(1)

LCD display(2)

Buzzer sound opening(3)

Alarm LED arrays
(top)

(4)

Alarm LED arrays (left)(5)

Alarm LED arrays(right)(6)

Infraredcommunication port

Main function
Displays a gas concentration, alarm, etc.
Gas concentration is updated every second (combustible gas:
every one or two seconds).
Emits a buzzer sound at an alarm. (Do not block it.)

The red lamp blinks in response to an alarm.

Used to carry out data communications with a PC when the datalogger management program is used.

- 16 -

3. Product Components

3-2. Names and functions for each part

Name

Main function▲/AIR button

Used to perform air calibration on the measurement screen. Or
used to increase a numeric value in the display/setting mode.

(8)▼/PUMP button

Used to turn ON/OFF the pump on the measurement screen. Or
used to reset an alarm in an alarm state.
In the display/setting mode, press this button to decrease anumeric value.

(9)

PEAK/ESC button

Used to switch the mode or display.

(10)

POWER/ENTER button

Used to turn ON/OFF the power.

(11)

Gas outlet (GAS OUT)

Exhausts the gas drawn into the gas monitor. (Do not block it.)(12)

Gas inlet (GAS IN)

Draws a gas into the gas monitor. Connects the accessory tube,
etc.

(13)

Charging indicator
lampLights up in red during charging and goes off when charging iscompleted.

(14)

Charging jack cover

Removed to connect an AC adapter and charge the batteries.

(15)

Buzzer sound opening

Emits a buzzer sound at an alarm. (Do not block it.)(16)

Battery unit screws

Turn these screws to detach and replace the battery unit.

(7)

CAUTION Do not jab the buzzer opening with a sharp-pointed item. The unit may malfunction or getdamaged, allowing water or foreign matter, etc. to get inside.
 Do not remove the panel sheet on the surface. The water-proof and dust-proof performances
will be deteriorated.
 Do not affix a label or the like on the infrared port. Infrared communications can no longer be
conducted.

- 17 -

3. Product Components

3-2. Names and functions for each part

<Display>

Item

Main function(1)

Operating status
display

Displays the operating status in the measuring mode.
A heart symbol blinks in the normal state.

(2)

Combustible gas
concentration display
Digital and bar display

Displays the gas concentration as a numeric value and a level in thebar graph.

(3)

Carbon monoxide
concentration display
Digital and bar display

Displays the gas concentration as a numeric value and a level in thebar graph.

(4)

Battery level icon

Displays the battery level. See NOTE for a guide for battery level.

(5)

Pump driving
indicator

Displays the drawing status in the measuring mode. Rotates at a
normal state.

(6)

Oxygen concentration
display
Digital and bar display

Displays the gas concentration as a numeric value and a level in thebar graph.

(7)

Carbon dioxide
concentration display
Digital and bar display

Displays the gas concentration as a numeric value
and a level in the bar graph.

NOTE The meanings of battery level icons are as follows:: Sufficient/: Low/: Needs charging
If the battery level further drops, the inside of the battery icon starts to blink ( The gas alarm function is an optional setting.
 When "NO ALARM" lights up, no gas alarm pattern is performed.
NO ALARM display- 18 -).

3. Product Components

3-2. Names and functions for each part<RX-8700 (with lithium ion battery unit BUL-8000)><Main Unit>

Name

Main function
Displays a gas concentration, alarm, etc. Gas concentration is
updated every second (combustible gas: every one or two
seconds).

(1)

LCD display(2)

Buzzer sound opening

Emits a buzzer sound at an alarm. (Do not block it.)(3)

Alarm LED arrays

The red lamp blinks in response to an alarm.

(4)

HC/O2/H2S [lowconcentration]measuring modeindicator lamp

Lights up (in green) when HC/O2/H2S [low concentration]measuring mode is entered.

(5)

H2S [highconcentration]measuring modeindicator lamp

Lights up (in green) when H2S [high concentration] measuringmode is entered.

(6)

Infraredcommunication port

Used to carry out data communications with a PC when the datalogger management program is used.

(7)▲/AIR button

Used to perform air calibration on the measurement screen. Or
used to increase a numeric value in the display/setting mode.
- 19 -

3. Product Components
Name
(8)

▼/PUMP button

3-2. Names and functions for each part
Main function
Used to turn ON/OFF the pump on the measurement screen. Or
used to reset an alarm in an alarm state.
In the display/setting mode, press this button to decrease anumeric value.

(9)

PEAK/L/H/ESC button

Used to switch the mode between the H2S [high concentration]measuring mode and HC/O2/H2S [low concentration] measuringmode on the measurement screen.
Or used to switch the mode or display in the display/setting mode.

(10)

POWER/ENTER button

Used to turn ON/OFF the power.

(11)

Gas outlet (GAS OUT)

Exhausts the gas drawn into the gas monitor. (Do not block it.)(12)

Gas inlet (GAS IN)

Draws a gas into the gas monitor. Connects the accessory tube,
etc.

(13)

Charging indicator
lampLights up in red during charging and goes off when charging iscompleted.

(14)

Charging jack cover

Removed to connect an AC adapter and charge the batteries.

(15)

Buzzer sound opening

Emits a buzzer sound at an alarm. (Do not block it.)(16)

Battery unit screws

Turn these screws to detach and replace the battery unit.

CAUTION Do not jab the buzzer opening with a sharp-pointed item. The unit may malfunction or getdamaged, allowing water or foreign matter, etc. to get inside.
 Do not remove the panel sheet on the surface. The water-proof and dust-proof performances
will be deteriorated.
 Do not affix a label or the like on the infrared port. Infrared communications can no longer be
conducted.

- 20 -

3. Product Components

3-2. Names and functions for each part

<Display (HC/O2/H2S [low concentration] measuring mode)>

Item

Main function(1)

Operating status
display

Displays the operating status in the measuring mode.
A heart symbol blinks in the normal state.

(2)

Combustible gas
concentration display
Digital and bar display

Displays the gas concentration as a numeric value and a level in thebar graph.
(HC concentration is displayed after isobutane conversion.)(3)

Hydrogen sulfide[low concentration]
concentration display
Digital and bar display

Displays the gas concentration as a numeric value and a level in thebar graph.

(4)

Battery level icon

Displays the battery level. See NOTE for a guide for battery level.

(5)

Pump driving
indicator

Displays the drawing status in the measuring mode. Rotates at a
normal state.

(6)

Oxygen concentration
display
Digital and bar display

Displays the gas concentration as a numeric value and a level in thebar graph.

- 21 -

3. Product Components

3-2. Names and functions for each part

<Display (H2S [high concentration] measuring mode)>

Item

Main function(1)

Operating status
display

Displays the operating status in the measuring mode.
A heart symbol blinks in the normal state.

(2)

Battery level icon

Displays the battery level. See NOTE for a guide for battery level.

(3)

Pump driving
indicator

Displays the drawing status in the measuring mode. Rotates at a
normal state.

(4)

Hydrogen sulfide[high concentration]
concentration display
Digital and bar display

Displays the gas concentration as a numeric value and a level in thebar graph.

NOTE The meanings of battery level icons are as follows:: Sufficient/: Low/: Needs charging
If the battery level further drops, the inside of the battery icon starts to blink ( The gas alarm function is an optional setting.
 When "NO ALARM" lights up, no gas alarm pattern is performed.
NO ALARM display- 22 -).

4. How to Use

4-1. Before using the gas monitor

44.

How to Use

4-1. Before using the gas monitor
Not only the first-time users but also the users who have already used the gas monitor must follow theoperating precautions.
Ignoring the precautions may damage the unit, resulting in inaccurate gas measurement.
Regarding the use, setting, and maintenance of gas detectors, it is recommended to refer to the standards
appropriate to the laws and regulations of each country.
Example) IEC 60079-29-2, EN60079-29-2, NFPD 70

4-2. Preparation for start-up
Before starting gas measurement, check the followings.
••••

Check that the battery level is sufficient.
Check that the filter inside the gas monitor is not contaminated or clogged.
Check that there is no bend or hole in the gas sampling hose and relay tube.
Check that the main unit, relay tube, filter tube, gas sampling hose and gas sampling probe areconnected properly in this order.

•

DANGER Perform charging of the lithium ion battery unit in a safe place.
 During use and storage, be sure not to point the gas inlet (GAS IN) and gas outlet (GAS OUT)
upward.

Gas outlet (GAS OUT)
Gas intlet (GAS IN)

NOTE

 After changing parameters by using an external device, make sure that the parameters are set
correctly before use.

- 23 -

4. How to Use

4-2. Preparation for start-up

4-2-1. Charging the lithium ion battery unit (BUL-8000(Z1))
When the gas monitor is used for the first time, or when the battery level is low, be sure to use thededicated AC adapter to charge the battery unit.

1

Open the charging jack cover of the lithium ion battery unit.

2

Insert the AC adapter
plug into the charging
jack.

Charging indicator lamp
Insert the plug of AC
adapter for charging to
the charging jack.

Charging jackPlug

AC adapter for charging

3

Insert the AC adapter to the outlet.
When charging is started, the charging indicator lamp lights up in red.
(Charging time: Three hours at the maximum until the battery unit is fully charged)
When charging is completed, the charging indicator lamp goes off.

4

When charging is completed, disconnect the AC adapter from the outlet.

5

Disconnect the AC adapter plug from the charging jack and attach the
charging jack cover.
Push the charging jack cover as far as it will go.

DANGER Charge the battery unit using the dedicated AC adapter in a safe place.
 Charge the battery unit at ambient temperatures between 0 to 40ºC.
 Do not use the gas monitor while charging it. Correct measurements cannot be obtained.
Furthermore, the batteries get deteriorated more quickly and may have shorter life.
 The charger is neither water-proof nor dust-proof. Do not charge the batteries while the gas
monitor is wet.
 The charger is not explosion-proof.

- 24 -

4. How to Use

4-2. Preparation for start-up

CAUTION
Do not pull the charging jack cover hard to open the cover in the step 1. It may get damaged.
Do not use the battery unit with the charging jack cover detached. Dust or water may get into
the gas monitor, causing it to malfunction. If the charging jack cover is damaged, replace thebattery unit with new one.
If the charging jack cover is not completely closed, water may get in from the charging jack.
The same thing may occur if a minute foreign substance gets stuck between the cover and theunit.
Disconnect the AC adapter from the outlet while it is not in use.

NOTE
During charging, the lithium ion battery unit may get hot, but this is not an abnormality.
The temperature of the unit is high immediately after charging is completed. Let it stand for 10
minutes or more before using it. Using the lithium ion battery unit while it is still hot may cause
erroneous measurement.
When a fully charged battery unit is recharged, the charging indicator lamp does not light up.

4-2-2. Detaching and attaching the battery unit
1

Loosen the two battery
unit screws on thebottom.

2

Detach the battery unit.

3

Attach a new battery unit
and then tighten the twobattery unit screws.
Attach the battery unit in the correct
direction with attention to theconnection terminal or projections.

<Lithium ion battery>
Battery unit screws

Connection
terminal- 25 -

4. How to Use

4-2. Preparation for start-up

CAUTION Turn off the power of the gas monitor before replacing the battery unit.
 Replace the battery unit in a safe place.
 If the battery unit screws are not tightened securely, the battery unit may drop off or water may
get in through the clearance. Water may also get in if a minute foreign substance is caught
between the battery unit and gas monitor.
 Do not damage the rubber seal. To maintain the water-proof and dust-proof performances, it isrecommended to replace the rubber seal every two years, whether or not it has anabnormality.

4-2-3. Connecting the gas sampling probe and gas sampling
hoses
Attach the gas sampling hose to the gas sampling probe.
Connect the relay tube, filter tube, gas sampling hose and gas sampling probe in this order securely to thegas inlet (GAS IN) of the main unit.

- 26 -

4. How to Use

4-2. Preparation for start-up

CAUTION Use only a gas sampling hose specified by RIKEN KEIKI.
 The gas sampling hose must be connected to the gas sampling probe before use so that no
foreign substance is drawn into it.
 Be sure to connect the gas sampling probe and gas sampling hose by fastening them byhand. Fastening them too tight using a tool may break the plastic part of the gas samplingprobe.

NOTE

 When connecting a part to the gas inlet (GAS IN), push the part until it clicks into place.

- 27 -

4. How to Use

4-3. How to start the gas monitor

4-3. How to start the gas monitor
When the power is turned on, self-diagnosis starts and then the measurement screen appears.

4-3-1. Power-on
Hold down the POWER/ENTER button (over three seconds) until the buzzer blips to turn on the power.
When the power is turned on, the LCD display changes automatically as shown below before themeasurement screen is displayed.

NOTE

 When the power is turned on, the LCD, lamps and buzzer start to operate. Before using the product,check that these operations function correctly.

1

Hold down the
POWER/ENTER button
for at least 3 seconds.

Hold down the
button until theentire LCD
display andalarm lamp lightup and thebuzzer blips.

RX-8500 LCD display

RX-8700 LCD display

▼

▼

▼

▼

▼

▼

All LCDs lightup

Date/time
display

Battery
voltage display

Pump warmup- 28 -

4. How to Use

4-3. How to start the gas monitor
▼

▼

▼

▼

▼

▼

▼

▼

▲
▼

▲
▼

▼

▼

Gas name
display

Full scale
display

ID display

The screens on
the right are
displayedalternately until
the ENTER
button ispressed.

2

Filterconnection
check

Press the ENTER
button.
The sensor warm-up operation is
performed for about 25 seconds.

- 29 -

4. How to Use

4-3. How to start the gas monitor

The buzzer blips twice and thenthe measurement screen isdisplayed.

CAUTION After start-up, perform air calibration (P. 36) before performing gas measurement.
 RX-8700 is started in the H2S [high concentration] measuring mode.
 Life time of data storage is 14 years if a back-up battery is used for preserving the data
content of parameter memory.

NOTE If any abnormality is detected in the sensor, a sensor abnormality
alarm is triggered just before entering the measuring mode. Pressthe ▼ button when a sensor abnormality alarm is triggered. The
sensor abnormality alarm is reset temporarily, and "- - -" appears
in the concentration display area of the gas with sensor
abnormality before starting measurement (the alarm cannot be
reset if all sensors have an abnormality).
In this case, promptly contact RIKEN KEIKI. Gas measurement
cannot be performed with a sensor having an abnormality.
 If there is an abnormality in the built-in clock, a fault alarm "FAIL
CLOCK" may be triggered. Press the ▼ button when the alarm istriggered. The fault alarm is temporarily reset, and measurement isstarted with incorrect clock time.

Display example(Oxygen sensor abnormality)

4-3-2. Switching the hydrogen sulfide measuring mode range
on RX-8700
RX-8700 switches the mode between the H2S [high concentration] measuring mode and HC/O2/H2S [lowconcentration] measuring mode.

Hold down the L/Hbutton (about one
second) and release it
when the buzzer blips
once.
H2S [high concentration]measuring mode

- 30 -

HC/O2/H2S[low concentration]measuring mode4. How to Use

4-4. Basic operating procedures

4-4. Basic operating proceduresThis mode is used on the measurement screen after power-on.

4-4-1. RX-8500 basic operating procedures<Measurement screen>Long pressing<Fault alarm state (self-latching)>(Low flow rate)<Air calibration mode>

Pressing
at thesame
time

Pressing at
the same time

<Manual memory mode><Calibration mode>Long pressing

Short pressing<Pump ON/OFF mode><Display/setting mode>- 31 -

4. How to Use

4-4. Basic operating procedures

4-4-2. RX-8700 basic operating proceduresLong
pressing(about1 second)

HC/O2/H2S <low concentration>measuring mode

H2S <high concentration>measuring mode

<Measurement screen>(HC/O2/H2S <low concentration>measuring mode)Long pressing<Fault alarm state (self-latching)>(Low flow rate)<Air calibration mode>

Pressing
at thesame
time

Pressing at
the same time<Calibration mode><Manual memory mode>Long pressing<Pump ON/OFF mode>Long
pressing(about3 seconds)<Display/setting mode>- 32 -

4. How to Use

4-5. Measurement

4-5. Measurement
Measure gas concentration on the measurement screen. Put the gas sampling probe close to themeasurement area.
Once gas concentration measurement is started, the gas monitor draws in a measuring gas for a certain
period of time and then displays a concentration value as a measurement result.

4-5-1. Gas concentration measurement
With the measurement screen displayed, put the gas sampling probe close to the measurement area andtake the reading on the LCD display.

<RX-8500>

Combustible gas
concentration(CH4: Methane): 0.0% LEL, 0 vol%Carbon monoxide
concentration: 0 ppm

Oxygen concentration: 20.9%Carbon dioxide
concentration: 0.00 vol%Battery level: Sufficient<RX-8700>
H2S [highconcentration]measuring mode
Hydrogen sulfide
concentration: 0 ppm

HC/O2/H2S [lowconcentration]measuring mode

Combustible gas
concentration(HC: Isobutane
converted): 0.0% LEL, 0 vol%Oxygen concentration: 20.9%Hydrogen sulfide
concentration: 0.0 ppm
Battery level: Sufficient- 33 -

4. How to Use

4-5. Measurement

DANGERWARNING WhileThe gasconducting
monitor ismeasurement
designed to draw
in a manhole
gases aroundor confined
it underspace,
the atmospheric
do not lean pressure.
over or look
If intothe manhole
excessivepressureor closed
is applied
space. to
It maythe gasleadinlet
to dangers(GAS IN)
becauseand outlet
oxygen-deficient(GAS OUT) ofair
the
orgas
other
gases may
monitor,measured
blow out.
gases may leak out from its inside and may cause dangerous conditions.
sure that excessive
is notappliedto them while
used.
 Be
Oxygen-deficient
air or pressureother gases
may
be discharged
from thegas exhausting outlet of the Dogasnotmonitor.
connect
Never
the sampling
inhale thehose
air ordirectlygases.to a measurement area with a pressure higher thanatmospheric pressure.
The internal
pipingsystemmay
be damaged.
 theHigh-concentration(100% LELor higher)
gases
may bedischarged
from the gas exhausting Whenairthecalibrationis performedin thecheck the atmosphere for freshness
outlet ofgas monitor.
Never usefire atmosphere,
near it.
beginning it.
interference
gases exist,
cannot be
theIf oxygen
concentration,
do thenot calibration
measure anything
butperformeda mixture properly,of air and before
When measuring
thus leading to dangers when the gas leaks.
 Issuance of a gas alarm indicates that there are extreme dangers. Take proper actions basedon your judgment.
 Before use, check that there remains sufficient battery power. When the gas monitor is used
for the first time or is not used for a long period, the batteries may be exhausted. Either fully
charge the batteries or replace them with new ones before use.
 Gas measurement cannot be performed with a low battery voltage. If the low battery voltage
alarm is triggered during use, turn off the power and promptly charge the batteries in a safe
place.
 Do not block the buzzer sound opening. No alarm sound can be heard.

CAUTION Before performing gas measurement, connect the gas sampling probe provided with the gas
monitor to prevent disturbances by air dust.
 When measuring concentrations of oxygen in inert gases for a long time, the carbon dioxide
concentration in the air must be 15% or less. When the gas monitor is used in the inert gas
with a carbon dioxide concentration higher than 15%, perform measurement in as short time
as possible.
 Do not use the gas monitor in a place with high oxygen concentration for a long time. The
oxygen sensor life may be shortened. Also, if the oxygen concentration is measured for a longtime in hydrogen sulfide with a concentration exceeding 6000 ppm, the indicated value may
decrease. Similarly, shorten the measurement time as much as possible.

NOTE

 In a low-temperature environment, the operating time is shortened due to the battery performance
property.
 At low temperatures, the responses of the LCD display may slow down.
 If a combustible gas with 100% LEL or higher concentration is drawn, adsorbed gases may remainin the gas sampling hose or gas sampling probe. After drawing a high-concentration combustiblegas, be sure to draw fresh air and perform air cleaning until the reading nears zero to remove
adsorbed gases. Performing air calibration before cleaning completely may result in inaccurate air
calibration, giving adverse influence on measurement. In such a case, remove the gas samplingprobe and hose and then perform air calibration to avoid inaccurate calibration.
 [RX-8700] To measure an area where high-concentration hydrogen sulfide may be present, use theH2S [high concentration] measuring mode.
 [RX-8700] To measure hydrogen sulfide concentration, check that hydrogen sulfide concentration isless than 100 ppm in the H2S [high concentration] measuring mode and then measure combustible
gas and oxygen concentrations in the HC/O2/H2S [low concentration] measuring mode. Drawing
high-concentration hydrogen sulfide in the HC/O2/H2S [low concentration] measuring mode may
damage the combustible gas, oxygen or low-concentration hydrogen sulfide sensor.

- 34 -

4. How to Use

4-5. Measurement

4-5-2. Range switching point
The display automatically switches to the vol% range when the concentration of a measured combustible
gas exceeds 100% LEL. When the concentration drops, the display returns to the %LEL range again. The
following shows an example of switching timing.

<Example of gas concentrations and range switching timing>(1) RX-8500
CH4 concentration

100%LEL(4.4vol%)%LEL range

vol% range

Switching point%LEL range

Switching point

Combustible gas concentration display•
CH4: Methane•
The range switching point is a lower explosive limit of a gas. It is 4.4 vol% for methane.
(2) RX-8700
HC concentration

100%LEL(1.3vol%)%LEL range

vol% range

Switching point%LEL range

Switching point

Combustible gas concentration display•
HC: Isobutane converted•
The range switching point is a lower explosive limit of a gas. It is 1.3 vol% for isobutane.

- 35 -

4. How to Use

4-6. Air calibration

4-6. Air calibration
Air calibration is zero adjustment to correctly measure the current gas concentration.

4-6-1. Attaching the CO2 removal filter (RX-8500)
To perform zero calibration for carbon dioxide (CO2), CO2 in the air needs to be removed using the CO2
removal filter.
Attach the CO2 removal filter so that the arrow (->) on the side is directed at the filter tube.

Filter tube side
Direct the arrow at the filter tube.

Stand the CO2 removal filter to use. With it laid horizontally, CO2 in the air may not be absorbed.
Correct use

Incorrect use

With the CO2 removal filter laid horizontally, air
passes through the shaded area and CO2
cannot be absorbed.

CO2 removal filter
Stand the CO2
removal filter to use.

Filter tube
CO2 removal filter

Filter tube

The number of usable times per filter depends on the carbon dioxide concentration in the air. It varies also
by the air tightness of CO2 removal filter, storage temperature or humidity.
The following table shows guide values assuming that each use takes one minute for drawing. However,
use the removal filter with a margin when the carbon dioxide concentration in the environment is unknown.
Measurement
environment
carbon dioxide (CO2)concentration
500ppm1000ppm
2000ppm
4000ppm

Estimated number of usable times
in consideration of storage
condition
Approx. 1000 times
Approx. 500 times
Approx. 200 times
Approx. 100 times- 36 -

4. How to Use

4-6. Air calibration

CAUTION Do not draw high-concentration carbon dioxide during zero calibration.
 Do not breathe on the inlet during zero calibration.
 Block ventilation to the air after using the CO2 removal filter. With the air mixed, the absorbent
absorbs carbon dioxide in the air, resulting in degraded absorption performance.
 Store the CO2 removal filter in a dry place away from direct sunlight.

NOTE

 The number of usable times per filter depends on the carbon dioxide concentration in the air. It
varies also by the air tightness of CO2 removal filter, storage temperature or humidity.
 The above table shows guide values assuming that each use takes one minute for drawing.
However, use the removal filter with a margin when the carbon dioxide concentration in theenvironment is unknown.

4-6-2. Air calibration procedure1RX-8500 LCD display

RX-8700 LCD display

▼

▼

▼

▼

Hold down the AIR buttonon the measurement
screen.
The air calibration screen isdisplayed.

Keep the AIR button pressed while
the screen shown in the right figure
is displayed.
Air calibration is not started if the
button is released before thescreen is displayed.
Press the ESC button to stop air
calibration.

- 37 -

4. How to Use

2

4-6. Air calibration

Release the AIR button
when the screen shown in
the right figure isdisplayed.
On RX-8500, nitrogen gas
calibration is performed next.
Pressing the ESC button skips
nitrogen gas calibration andperforms air calibration.
On RX-8700, nitrogen gas
calibration is not performed.

3

For RX-8500, attach theCO2 removal filter andpress the ENTER button.
See "4-6-1. Attaching the CO2
removal filter" for how to attach theCO2 removal filter.
▼

▼
▼
▼
▼
▼
▼
▼

When air calibration is completed,the screen shown in the right figure
is displayed.

WARNING When air calibration is performed in the atmosphere, check the atmosphere for freshness
before beginning it. If interference gases exist, air calibration cannot be performed, thus
leading to dangers when the gas leaks.
 Perform air calibration under pressure and temperature/humidity conditions close to those in
the operating environment and in fresh air.
 Perform air calibration after the reading is stabilized.
 If there is a sudden temperature change of 15ºC or more between the storage and operational
locations, turn on the power of the gas monitor, let it stand for about 10 minutes in a similar
environment to the operational location, and perform air calibration in fresh air before using it.
 [RX-8500] The amount of carbon dioxide in the air is about 300 to 500 ppm. If air calibration
for the carbon dioxide sensor is performed while directly drawing air where carbon dioxide ispresent, correct measurement of gas concentration becomes impossible. Before performing
air calibration on RX-8500, attach the CO2 removal filter and draw air for at least one minute.

- 38 -

4. How to Use

4-6. Air calibration

NOTE If air calibration fails, "FAIL - AIR CAL" is displayed along with thename of gas sensor which has become faulty. Press the ▼ button
to reset the fault alarm (calibration failure). When the alarm is reset,
the value before calibration is displayed.
 [RX-8500] Do not draw high-concentration carbon dioxide during air
calibration.
 [RX-8500] Do not breathe on the inlet (GAS IN) during air
Air calibration failure display example
calibration.
Oxygen (O2) sensor
 [RX-8500] Block ventilation to the air after using the carbon dioxide
removal filter. With the air mixed, the absorbent absorbs carbon dioxide in the air, resulting indegraded absorption performance.
 [RX-8700] Perform air calibration in each of the two modes (H2S [high concentration] measuringmode and HC/O2/H2S [low concentration] measuring mode).

- 39 -

4. How to Use

4-7. Manual memory

4-7. Manual memory
Up tO256 arbitrary instantaneous values during measurement can be recorded.
When the number of recorded data points reaches the maximum, recorded data will be overwritten,
starting from the oldest data.

1

Hold down the ▲ and PEAK buttons on themeasurement screen.
The memory number, recorded date and recorded concentration
are displayed in turn as shown below.
Display example (RX-8500)

Memory No.

Recorded date

Recorded concentration

Press the ESC button to skip recording the displayed contents.
The measurement screen returns.

2

Press the ENTER button.
"END" is displayed on the screen, and the memory number, dateand gas concentration at the time the ENTER button is pressed
are recorded.
After recording the data, the measurement screen returns
automatically.

NOTE If PEAK and ▲ buttons are not pressed at the same time, the air calibration (P. 36) ordisplay/setting (P. 43) screen is displayed. In this case, release both buttons and try again after
displaying the measurement screen.
 If there is no recorded data, “NO DATA” is displayed.

- 40 -

4. How to Use

4-8. Stopping the pump (PUMP OFF mode)

4-8. Stopping the pump (PUMP OFF mode)
The pump operation can be stopped.

1

Hold down the PUMP button on themeasurement screen (about five seconds).
The pump stops operating.
The buzzer blips twice every three minutes or so while the pump
operation is stopped.

2

Press the PUMP button to activate the pump.
The measurement screen returns.

WARNING No alarm is triggered under any circumstances in the PUMP OFF state.
 The measuring mode does not return automatically in the PUMP OFF state.

- 41 -

4. How to Use

4-9. Power-off

4-9. Power-off
CAUTION If the concentration display is not reset to zero (or 20.9% for the oxygen concentration display)after measurement is completed, leave the gas monitor in fresh air until the display returns tozero and then turn off the power.

Keep the POWER/ENTER button pressed.
To turn off the power, hold down the POWER/ENTER button
after the display returns to zero (0, or 20.9% for oxygen) in asafe place.
The buzzer blips three times and "TURN OFF" appears on
the display before the power is turned off.

Power-offNOTE To turn off the power, keep the button pressed until the display disappears.
 If the display is not zero when the power is turned off, a purge operation may be performed for 30
seconds at the maximum on RX-8500 or 60 seconds at the maximum on RX-8700 to clean the insideof the gas monitor.

<RX-8500><RX-8700>
A purge operation is performed in the H2S [high concentration]measuring mode (HI) and then the HC/O2/H2S [lowconcentration] measuring mode (LO).

- 42 -

5. Display/setting Mode

5-1. Display/setting mode

55.

Display/setting Mode

5-1. Display/setting modeThis mode allows users to display or change various settings.

RX-8500
1

RX-8700

Press the PEAK button on themeasurement screen.
The following display/setting screens are
displayed in turn by pressing the PEAK
button.
･ Press PEAK once: PEAK display/clear･ Press PEAK twice: Alarm setpoint
display･ Press PEAK three times: Clock display･ Press PEAK four times: Station ID
display･ Press PEAK five times: Log data
display･ Press PEAK six times: Return to themeasurement screen

NOTE

1

Hold down the PEAK button on
the measurement screen(about three seconds).

2

Release the button when thebuzzer blips twice.
･ Hold down PEAK: PEAK display/clear

3

Press the PEAK button again.
The following display/setting screens are
displayed in turn by pressing the PEAK
button.
･ Hold down PEAK and then press it
once: Alarm setpoint display･ Hold down PEAK and then press it
twice: Clock display･ Hold down PEAK and then press it threetimes: Station ID display･ Hold down PEAK and then press it fourtimes: Log data display･ Hold down PEAK and then press it fivetimes: Return to the measurement
screen When the unoperated period lasts about 20 seconds, the measurement screen returns automatically.
 [RX-8700] When the button is released after the buzzer blips once in the step 2, it causes a switch
between the H2S [high concentration] measuring mode and HC/O2/H2S [low concentration]measuring mode and fails to enter the display/setting mode.
 [RX-8700] The display/setting mode can be entered from either of the two modes (H2S [highconcentration] measuring mode and HC/O2/H2S [low concentration] measuring mode).

- 43 -

5. Display/setting Mode

Item
PEAK display/clear

5-1. Display/setting mode

Details

LCD display

Displays the maximum
concentration (or minimum
concentration for oxygen)obtained during
measurement from poweron to the present. Clears apeak value as well.

PEAK display on RX-8500

Remarks
Go to thedisplay/clear
screen(P. 45)

Alarm setpoint display(Full scale/alarm
setpoint display/gas
alarm test)

Displays the full scalevalue and first and second
alarm setpoints, andallows users to check
alarm activation.
* The gas alarm function isan optional function.

Clock display

Displays the current date
and time.

Station ID display

Displays station IDs
registered in advance.
ID selection is alsoavailable.

Press theENTER button
to go to thedisplay/selection
screen(P. 47)

Log data display

Displays data recorded in
the manual memory.

Press theENTER button
to go to thedisplay screen(P. 48)- 44 -

Press theENTER button
to go to thedisplay screen(P. 46)

5. Display/setting Mode

5-2. PEAK display/clear

5-2. PEAK display/clear
This item displays or clears the maximum concentration (or minimum concentration for oxygen) obtained
during measurement from power-on to the present.

1

Display the screen shown in the right figure oneach model.
RX-8500

RX-8700

Press the PEAK button once
on the measurement screen.

Hold down the PEAK buttonon the measurement screen(about three seconds).

2

Hold down the ▼ button to clear PEAK value.

3

Release the ▼ button when "RELEASE" isdisplayed.

PEAK display on RX-8500

PEAK value has been cleared.
After clearing the value, the buzzer blips and the screen in thestep 1 returns.

NOTE When the unoperated period lasts about 20 seconds, the screen in the step 1 is replaced with themeasurement screen.

- 45 -

5. Display/setting Mode

5-3. Full scale/alarm setpoint display/gas alarm test (optional function)

5-3. Full scale/alarm setpoint display/gas alarm test
(optional function)
This item displays the full scale value and first and second alarm setpoints, and allows users to check
alarm activation.
Normally the gas alarm function is set to OFF and unavailable (optional function). To use this function,please contact RIKEN KEIKI.

1

Display the screen shown in the right figure oneach model.
"ALARM-P" and "YES/ENT" are displayed alternately in the lower
part of the screen.

RX-8500

RX-8700

Press the PEAK button twiceon the measurement screen.

•

•

▲
▼

Hold down the PEAK
button on themeasurement screen(about three seconds).
Press the PEAK button
once.

2

Press the ENTER button.

3

Press the ▲/▼ button to display the full scale or
first/second alarm setpoint value.
Display example of the case without alarm setpoints on RX-8500

4Full scale valueFirst alarm setpoint

Second alarm setpoint

The OVER alarm (overscale) activation occurs in an
alarm test.

"OFF" appears in theconcentration display area.

"OFF" appears in theconcentration display area.

Display a desired screen and press the ENTER
button.
The alarm LED arrays blink in red, allowing the user to check thealarm activation of the screen displayed.

5

Press the ENTER or ESC button to stop thealarm activation.
Pressing the ENTER button stops the alarm activation.
Pressing the ESC button stops the alarm activation and thenreturns to the screen in the step 1.

- 46 -

5. Display/setting Mode

5-4. Station ID display

NOTE When the unoperated period lasts about 20 seconds, the screen in the step 1 is replaced with themeasurement screen.
 No display switch is made during alarm test.

5-4. Station ID display
This item displays the registered station IDs and allows users to make a selection.

1

Display the screen shown in the right figure oneach model.
RX-8500

RX-8700

Press the PEAK button fourtimes on the measurement
screen.

••Hold down the PEAK
button on themeasurement screen(about three seconds).
Press the PEAK button
three times.

2

Press the ENTER button.

3

Select station ID with the ▲/▼ button.
When an ID change is not necessary, press the ESC button.

4

Press the ENTER button.
When the ID display is finished, the buzzer blips and the screen in
the step 1 returns.

NOTE When the unoperated period lasts about 20 seconds, the screen in thestep 1 is replaced with the measurement screen.
 When the unit is used for the first time, station ID is displayed as shownin the right figure.
 On the gas monitor, IDs from ST-ID000 to ST-ID127 have beenregistered, unless otherwise specified.
 The data logger management program (optional) is required to registeror change an ID.
Please contact RIKEN KEIKI for more information.

- 47 -

5. Display/setting Mode

5-5. Log data display

5-5. Log data display
This item displays the gas concentration data recorded in the manual memory.

1

Display the screen shown in the right figure oneach model.
RX-8500

RX-8700

Press the PEAK button fourtimes on the measurement
screen.

••Hold down the PEAK
button on themeasurement screen(about three seconds).
Press the PEAK button
three times.

2

Press the ENTER button.

3

Select log data with the ▲/▼ button and thenpress the ENTER button.
The concentration value of the selected log data is displayed.
Press the ESC button to return to the screen in the step 1.

4

Press the ENTER button.

Display example on RX-

When the log data display is finished, the buzzer blips and the8500

screen in the step 2 returns.

NOTE When the unoperated period lasts about 20 seconds, the screen in the step 1 or 3 is replaced withthe measurement screen.

- 48 -

6. User mode

6-1. Displayng user mode

6
6.

User mode

6-1. Displayng user modeThis mode allows users to display or change various settings.

1

With the power turned off, press the POWER
button, ▲ button and ▼ button at the same
time.

2

Release the buttons when the buzzer blips.

3Enter the password “0405”, then press the
ENTER button.
Select the numbers with ▲ button and ▼ button, then press the
ENTER button to set.

4

Press the ▲ button and ▼ button to select anitem to be set or displayed, then using the
ENTER button, go to the setting or display
screen.

5

Once setting are complete, press the ▲ buttonand ▼ button on the user mode menu several
times to select “START”, then press the ENTER
button.
The product operates in the same way as when thte power has
just been turned on and proceeds to the measurement screen.

Item

Date and time setting

Details

LCD display

Remarks

Press the ENTER
button to goto theselection screen（P.51）

Set the date and time.

- 49 -

6. User mode

項目

6-1. Displayng user mode

LCD 表示内容

備考

ROM/SUM display

Displays the program
number and SUM valueof the product.

Press the ENTER
button to goto thedisplay screen（P.51）

Suppression setting:
ON/OFF

Set the suppression
ON/OFF.

Press the ENTER
button to goto theselection screen（P.52）

PEAK clear setting:
ON/OFF

Set ON/OFF the displayof the function to reset
the PEAK value in thesetting/display mode,turn.

Press the ENTER
button to goto theselection screen（P.53）

Gas calibration
function setting:
ON/OFF

Set the gas calibration
function ON/OFF.

Press the ENTER
button to goto theselection screen（P.53）

Station ID display
setting: ON/OFF

Set ON/OFF the displayof the station ID in thesetting/display mode.

Press the ENTER
button to goto theselection screen（P.54）

Measurement start

Proceed to themeasurement screen.

Press the ENTER
button to go to themeasurement
screen- 50 -

6. User mode

6-2. Date and time settingThis sets the date and time of the internal clock.

1

Press the ▲ and ▲ button on the user modemenu to select “DATE”, then press the ENTER
button.
The date and time setting screen is displayed.
The item currently blinking can be set.

2

Press the ▲ and ▲ button to select therequired setting item, then press the ENTER
button.
Set the date and time in the sequence year -> month -> day ->hour -> minute.
Press the ENTER button after setting the “minute” item. “END”
appears and the display returns to the user mode menu.

6-3. ROM/SUM display
This displays the program number and SUM value of the product.
* This is not normally used by the user.

1

Press the ▲ and ▲ button on the user modemenu to select “ROM/SUM”, then press the
ENTER button.

The ROM/SUM screen is displayed.

2

Press the MODE button.
“END” appears and the display returns to the user mode menu.

- 51 -

6. User mode

6-4. Suppression setting: ON/OFF

6-4. Suppression setting: ON/OFF
Set suppression to ON or OFF for each sensor.
Sensors for gas detection are affected by temperature, humidity and other characteristics depending on
the environment to use them. They are also much affected by interference of measurement gas.
The reading might be fluctuated around zero due to influence of the environment and interference
Zero suppression function makes reading fluctuation around zero less notified. This function is used tohide (suppress) the fluctuation of the reading less than the setting value, indicating zero (AIR for oxygen).

1

Press the ▲ and ▲ button on the user modemenu to select “SUPPRESS”, then press the
ENTER button.

2

Press the ▲ and ▲ button to select thesensor.

3

Press the ▲ and ▲ button to select ON or OFF.
“END” appears and the display returns to the display of theprocedure 2.

＜Suppression values＞
Suppression
value
Suppression
type
Minus
suppression
Minussuppression
type

Combustible
gas

O2

CO

H2S
【Low】

H2S
【High】

CO2-

20.9 ± 0.5 vol%(20.4 - 21.4 vol%)20 - 30 ppm

2.0 - 3.0 ppm

20 - 30 ppm--

Cut air

Smoothing

Smoothing

Smoothing--5 %LEL-0.5 vol%-50 ppm-5.0 ppm-50 ppm-1.00 vol%Cut off

Cut off

Cut off

Cut off

Cut off

Cut off- 52 -

6. User mode

6-5. PEAK clear setting: ON/OFF

6-5. PEAK clear setting: ON/OFF
This lets you enable and disable the PEAK clear function in the display/setting mode.

1

Press the ▲ and ▲ button on the user modemenu to select “PEAK CLR”, then press the
ENTER button.

2

Press the ▲ and ▲ button to select ON or OFF,then press the ENTER button.

6-6. Gas calibration function setting: ON/OFF
This lets you enable(ON) and disable(OFF) the gas calibration mode.

1

Press the ▲ and ▲ button on the user modemenu to select “DISP CAL”, then press the
ENTER button.

2

Press the ▲ and ▲ button to select ON or OFF,then press the ENTER button.

- 53 -

6. User mode

6-7. Station ID display setting: ON/OFF

6-7. Station ID display setting: ON/OFF
This lets you enable or disable the station ID display and selection in the display/seting mode. When set toOFF, the station ID can not be displayed and selected.

1

Press the ▲ and ▲ button on the user modemenu to select “DISP ID”, then press the
ENTER button.

2

Press the ▲ and ▲ button to select ON or OFF,then press the ENTER button.

- 54 -

7. Alarm Function

Gas alarm activation

7
7.

Alarm Function

Gas alarm activation
Normally the gas alarm function is set to OFF and unavailable (optional function). To use this function,please contact RIKEN KEIKI.
Gas alarm: Triggered when the concentration of detected gas reaches or exceeds the alarm setpointvalue. (Self-latching)
Alarm display: Notifies users of an alarm by blinking the concentration display of the subject gas,sounding the buzzer and lighting the lamp.
Alarm types: First alarm (WARNING), second alarm (ALARM), OVER alarm and M OVER alarm (minus
sensor failure)<Default settings>
M OVERalarm-10.0%LEL

Gas alarm typeFirst alarm

Second alarm

OVER alarm

Methan (CH4)
Oxygen (O2)

10.0%LEL

50.0%LEL

100.0vol%19.5vol%

25.0vol%

40.0vol％-1.0vol%

Carbon monoxide (CO)Carbon dioxide (CO2)
Isobutylene (i-C4H10))
Oxygen (O2)
Hydrogen sulfide (H2S)
<low>

25ppm
1.00vol%
10.0%LEL
19.5vol%

50ppm
3.00vol%
50.0%LEL
25.0vol%

1000ppm
20.0vol%
100.0vol%40.0vol%-100ppm-2.00vol%-10.0%LEL-1.0vol%

5.0ppm30.0ppm

100.0ppm-10.0ppm

5ppm

30ppm

1000ppm-100ppm

RX-8500

RX-8700

Hydrogen sulfide (H2S)<High><List of Gas Alarms>
Gas alarm type

Sounding
buzzerBlinking alarm
LED arrays

LCD display

First alarm
Repeatedlysounds strong andweak beeps atabout 1-second
intervals.
"Beep, beep"
Repeatedly blinks
at about 1-second
intervals.
Blinks the gas
concentration and
WARNING
displays.

Second alarm
Repeatedlysounds strong andweak beeps atabout 0.5 second
intervals:"Beep, beep,
beep, beep"
Repeatedly blinks
at about 0.5second intervals.
Blinks the gas
concentration and
ALARM displays.

- 55 -

OVER alarm
Repeatedlysounds strong andweak beeps atabout 0.5 second
intervals:"Beep, beep,
beep, beep"
Repeatedly blinks
at about 0.5second intervals.
Blinks the gas
concentration and
OVER displays.

M OVER alarm
Repeatedlysounds intermittent
beeps at about
one-second
intervals. "Beepbeep, beep-beep"
Repeatedly blinks
at about 1-second
intervals.
Blink “∪∪∪” andOVER displays.

7. Alarm Function

WARNING A gas alarm indicates the presence of extreme danger. The user must take appropriate action after
taking appropriate steps to ensure safety.

NOTE

 Responses to an alarm can be checked using the alarm test in display mode. Note, however, thatthe gas concentration value will not blink in alarm tests.

Fault alarm activation"Fault alarm" is triggered when an abnormality is detected in the gas monitor. (Self-latching)In response to a fault alarm, the buzzer sounds and alarm LED arrays blink.
• Sounding buzzer: Repeatedly sounds intermittent beeps at about one-second intervals. "Beep-beep,
beep-beep"• Blinking alarm LED arrays: Repeatedly blinks at about one-second intervals.
<Fault alarm activation on RX-8500>
The alarm LED arrays on the top, left and rightblink.

<Fault alarm activation on RX-8700>
Only the alarm LED arrays on the top blink.

Beep-beep,
beep-beep

Beep-beep,
beep-beep

There are following alarm types: low flow rate, battery voltage abnormalities, calibration failure, sensor
abnormalities, system abnormalities and clock abnormalities.
The following shows display examples of fault alarms.

(RX-8500)(RX-8700: Measuring H2S)

(RX-8700: Measuring lowconcentration hydrogen sulfide)

Low flow rate
(Fault alarm will be activated if the flow rate lowers under 350ml/min.)Battery voltage abnormalities

Calibration failure- 56 -

Sensor abnormalities

7. Alarm Function

System abnormalities

Fault alarm activation

Clock abnormalities

If a fault alarm is triggered, determine the cause and take appropriate action.
If the gas monitor has problems and is repeatedly malfunctioning, contact RIKEN KEIKI immediately.

NOTE

 For information on malfunctions (error messages), see "Troubleshooting" (P.71).

- 57 -

8. Maintenace

8-1. Maintenance intervals and items

8
8.

Maintenace

The gas monitor is an important instrument for the purpose of safety.
To maintain the performance of the gas monitor and improve the reliability of safety, perform a regular
maintenance.

8-1. Maintenance intervals and items
Perform the following maintenance regularly before use.
••

Daily maintenance: Perform maintenance before beginning to work.
Regular maintenance: Perform maintenance once or more for every six months to maintain theperformance as a safety unit.
Maintenance
item

Maintenance content

Daily
maintenanceRegularmaintenanceBattery level

Check that the battery level is sufficient.

○○

Concentration
display check

Make the gas monitor draw in fresh air. Check thatthe concentration display value is zero (0, or 20.9
vol% for the oxygen concentration display). If it is
not zero (0, or 20.9 vol% for the oxygen
concentration display), perform air calibration.

○○

Flow rate
check

Check the flow rate indicator for abnormalities.

○○

Filter check

Check the dust filter for dust or clogging.

○

○

Span
adjustment

Perform span adjustment using a calibration gas.

―○

Gas Alarm
Check

Check the gas alarm by using the calibration gas.

○○

WARNING If any abnormality is found in the gas monitor, promptly contact RIKEN KEIKI.

NOTE

 Perform span adjustment using a calibration gas at least once every six months.
 The span adjustment requires dedicated equipment and creation of calibration gas. Therefore, contact
RIKEN KEIKI for span adjustment.
 The built-in sensors of the gas monitor have a validity period and must be replaced regularly.
 The sensor life has expired if, for example, the sensors cannot be calibrated in span adjustment, thereadings do not come back after air calibration, or the readings fluctuate. In this case, contact RIKEN
KEIKI. Note that the warranty period is one year.
- 58 -

8. Maintenace

8-1. Maintenance intervals and items

About maintenance services
We provide services on regular maintenance including span adjustment, other adjustments andmaintenance.
To make the calibration gas, dedicated tools, such as a gas cylinder of the specified concentration andgas sampling bag, must be used.
Our qualified service engineers have expertise and knowledge on the dedicated tools used for services,along with other products. To maintain the safety operation of the gas monitor, please use ourmaintenance service.
The followings are typical maintenance services. Contact RIKEN KEIKI for more information.

<Main services>
Item
Battery level
check

Details
Checks the battery level.

Concentration
display check

Verifies that the concentration display value is zero (0, or 20.9 vol% for the oxygen
concentration display) using a zero gas.
Performs air calibration if the reading is incorrect.

Flow rate check

Checks the flow rate using an external flow meter.

Filter check

Checks the dust filter for dust or clogging.
Replaces a dirty or clogged dust filter.

Spanadjustment

Performs span adjustment using a calibration gas.

Cleaning andrepair of the unit
(visualdiagnosis)

Checks dust or damage on the surface of the unit, cleans and repairs such parts.
Replaces parts which are cracked or damaged.

Unit operation
check

Operates the buttons to check the operation of functions and parameters, etc.

Replacement ofconsumableparts

Replaces consumable parts, such as a sensor, filter and pump.

- 59 -

8. Maintenace

8-2. Span adjustment

8-2. Span adjustment
Perform span adjustment of sensors using a calibration gas more than once every six months.

8-2-1. Preparation
The zero and span adjustment requires dedicated equipment and a calibration gas (dry). Please contact
RIKEN KEIKI .

<Required Equipment/Material>
Calibration gas (optional)
Gas sampling bag (optional)

8-2-2. How to connect
Connect the devices as shown below to perform span adjustment.
Gas samplingprobe(with a tube)
Gas
samplingbag

Gas outlet(GAS OUT)

Gas inlet(GAS IN)WARNING
Do not apply pressure to the gas sampling bag after attaching it. It may cause a calibration gas
to leak inside and result in a calibration failure.
Calibration gas
A calibration gas uses a hazardous gas (combustible gas, toxic gas, oxygen deficiency, etc.).
Handle the gas and related jigs and tools with careful attention to the followings.
Gas sampling bag
Use different gas sampling bags for each gas type and concentration to perform accurate
calibration.
Place for span adjustment
Do not perform calibration in a confined space.
Perform span adjustment in a place where no silicone, spray can gases, etc. is used.
Perform calibration indoors at normal temperatures without remarkable fluctuation (within ±5ºC).
A calibration gas uses a hazardous gas (combustible gas, toxic gas, oxygen deficiency, etc.).
Therefore, be sure to perform calibration in an exhaust booth or collect the calibration gas inan exhaust bag.

CAUTION
Do not use a lighter gas to check the sensitivity of the gas monitor. A constituent of the lighter
gas may deteriorate the sensor performances.
It is recommended that zero adjustment and span adjustment be performed after 2 hours havepassed since the power was turned on. In addition, please perform each work after introducing
zero adjustment and span adjustment gas for 60 seconds or more.

- 60 -

8. Maintenace

8-2. Span adjustment

8-2-3. Span adjustment procedure
Perform the span adjustment using the procedure shown below.

1

Prepare an optional calibration gas and set ofgas sampling bags.

2

Check that the relay tube, filter tube, gas
sampling hose and gas sampling probe areconnected to the gas inlet (GAS IN) of the gas
monitor.

3

Check that themeasurement screen isdisplayed on the gas
monitor.

4

Perform air calibration.

Measurement screen on
RX-8500

See "4-6. Air calibration". (P. 36)
For RX-8700, perform air calibration in each of the two modes(H2S [high concentration] measuring mode and HC/O2/H2S [lowconcentration] measuring mode). Be sure to perform air
calibration before performing gas sensitivity calibration.

5

Collect a calibration gas in each gas samplingbag.

6

Hold down the ▲ and ▼ buttons at the sametime on the measurement screen (over one
second).
The gas monitor enters the calibration mode.

7

Select the gas type to be calibrated with the▲/▼ button.
Pressing the ENTER button while "ESCAPE" is displayed returns
to the measurement screen.

<Calibration mode display on RX-8500>- 61 -

Measurement screen on
RX-8700

8. Maintenace

8-2. Span adjustment

CH4 %LEL adjustment

CH4 vol% adjustment

O2 % adjustment

CO ppm adjustment

CO2 vol% adjustment- 62 -

8. Maintenace

8-2. Span adjustment<Calibration mode display on RX-8700>

HC %LEL adjustment

8

HC vol% adjustment

O2 % adjustment

H2S ppm adjustment<low concentration>

H2S ppm adjustment<high concentration>

Press the ENTER button when the screen isdisplayed.
The concentration display blinks to indicate that calibration isready.

9

Connect the gas sampling bag containing thecalibration gas which is the same as theselected gas type to the gas sampling probe
connected to the gas monitor. Then introduce
the gas into the gas monitor.
Wait until the concentration display is stabilized.

10

When the concentration display is stabilized,
adjust it to the calibration gas concentration
using the ▲/▼ button.

▲▼

Display example on RX8500(Methane (CH4) %LEL
calibration)

11

Press the ENTER button.
"END" appears when the calibration has finished.

- 63 -

8. Maintenace

8-2. Span adjustment

12

Perform calibration for other gas types in thesame manner.

13

Return to the measurement screen whencalibration for all gas types has finished.
The measurement screen does not return automatically in thecalibration mode.
To return to the measurement screen from the calibration mode,press the ▲/▼ button, select "ESCAPE" and then press the
ENTER button.

WARNING Return to the measurement screen when calibration has finished. The measurement screen
does not return automatically in the calibration mode.

NOTE If the ▲ and ▼ buttons are not pressed at the same time, the air calibration (P. 36) screen is displayed.
In this case, release both buttons and try again.
 While calibration is in process, press the ESC button to stop the process. The measurement screen
returns.

- 64 -

8. Maintenace

8-3. How to clean

8-3. How to clean
Clean the gas monitor if it becomes extremely dirty. The gas monitor must be turned off while cleaning it.
Use a waste cloth or the like to remove dust. Do not use water or organic solvent for cleaning because
they may cause malfunctions.
If the inside of the gas sampling hose is extremely contaminated, clean it with dry air, etc. to avoid
adverse influence on gas measurement.

CAUTION When cleaning the gas monitor, do not splash water over it or use organic solvents such as
alcohol and benzine on it. Otherwise, it may cause discoloration or damage to the surface ofthe gas monitor or a sensor failure.

NOTE When the gas monitor gets wet, water may remain in the buzzer sound opening or grooves. Drain
water as follows:(1) Wipe away moisture on the gas monitor thoroughly using a dry towel, cloth, etc.
(2) While holding the gas monitor firmly, shake it about ten times with the buzzer sound opening facing
downward.
(3) Wipe away moisture coming out from the inside thoroughly using a towel, cloth, etc.
(4) Place the gas monitor on a dry towel, cloth, etc. and let it stand at normal temperatures.

- 65 -

8. Maintenace

8-4. Parts replacement

8-4. Parts replacement
8-4-1. Sensor replacement
The built-in sensors of the gas monitor must be replaced regularly.
See the regular replacement parts (P. 68) for recommended replacement intervals.
The sensor life has expired if, for example, the sensors cannot be adjusted in calibration, the readings do
not come back after air calibration, or the readings fluctuate.
In this case, contact RIKEN KEIKI.

8-4-2. Replacement procedure for gas sampling probe dust
filter
The gas sampling probe has a built-in dust filter.
Because the dust filter may gradually get dirty or clogged over time, it must be replaced regularly
according to the operating conditions.
It must be replaced especially when it shows a sign of water absorption, low flow rate or contamination.

1

Rotate the end of the probe
counterclockwise and removeit.
A round dust filter is contained here.
Check it for contamination or clogging.
Replace the dust filter if it is contaminatedheavily or clogged.

2

Take out the filter and replace
it with new one.

3

Reattach the filter case.

NOTE Use only the filters specified by RIKEN KEIKI.
 The dust filter of the gas sampling probe is different from that of the filter tube. Use the specified filter
for each part.
 See the regular replacement parts (P. 68) for a replacement filter.

- 66 -

8. Maintenace

8-4. Parts replacement

8-4-3. Replacement procedure for filter tube dust filter
1

Loosen the cap (black) andremove it.

Cap (black)

Joint

2

3

As shown in the right figure, takeout the dust filter from the cap(black) and replace it with newone.

O-ring (S14)
Filter* The mesh sideshould face theO-ring (S14).

Reattach the cap (black).
Cap (black)

NOTE Use only the filters specified by RIKEN KEIKI.
 The dust filter of the gas sampling probe is different from that of the filter tube. Use the specified filter
for each part.
 See the regular replacement parts (P. 68) for a replacement filter.

8-4-4. Replacement procedure for filter tube absorbent
cotton1

Cut an absorbent cotton to thesize shown in the right figure(about 1.3 g) and round it into ashape.

2

Loosen the cap and remove it.

3

Replace the absorbent cotton.

Absorbent
cottonCap (black)Put the absorbent cotton into the pipe
without a gap between the pipe and cotton.

4

Pipe

Reattach the cap (black).

- 67 -

Absorbent
cotton8. Maintenace

8-4. Parts replacement

8-4-5. Replacement of regular replacement parts
Replace the regular replacement parts of the gas monitor according to the recommended intervals.

<List of Recommended Regular Replacement Parts>
Item

Maintenanceintervals

Replacement
intervals
6 months 1 year
6 months 1 year
6 months 1 year
6 months 1 year

Quantity

Internal filter

6 months

1 pc

Dust filter (10 pcs for gas
sampling probe)

6 months

Dust filter (10 pcs for filter tube)

6 months

Absorbent cotton (25 g for filter
tube)

6 months

CO2 removal filter

6 months

1 year

1 pc

1 pc
1 pc
1.3 g

Remarks*
Part number 4181 5452
30Part number 4777 9022
50Part number 1879 0011
10RX-8500 onlyPart number 0913 0028
30

Combustible gas (CH4)/
carbon dioxide (CO2) sensor
Carbon monoxide (CO) sensor

6 months

5 years

1 pc

RX-8500 only*

6 months

1 year1 pc

Oxygen (O2) sensor

6 months

1 year

1 pc

Combustible gas (HC) sensor
Hydrogen sulfide (H2S) [lowconcentration] sensor
Hydrogen sulfide (H2S) [highconcentration] sensor
Pump unit (RP-11)
Rubber seals
Tubes

6 months

5 years

1 pc

RX-8500 only*
Shared by RX-8500 and
RX-8700*
RX-8700 only*

6 months

1 year

1 pc

RX-8700 only*

6 months

1 year

1 pc

RX-8700 only*

6 months
6 months

1 - 2 years
2 years
3 - 8 years

1 pc
1 set
1 set

*
*
*
Part number 4777 9025
Protection film (5 pcs)
1 pc
70
About 500 cycles ofLithium ion battery pack1 pc
charging and(For BUL-8000)
discharging* The operation must be checked after replacement by a qualified service engineer. For the stable
operation of the gas monitor and safety, ask a qualified service engineer to take care of replacement of
the parts. Please contact RIKEN KEIKI.

NOTE

 The above replacement intervals are recommendation only. The intervals may change depending on
the operating conditions. These intervals do not mean the warranty periods either. The result of theregular maintenance may determine when to replace the parts.

- 68 -

9. Storage and disposal
for a long time

9-1. Procedures to store the gas monitor or leave it

99.

Storage and disposal

9-1. Procedures to store the gas monitor or leave it
for a long time
The gas monitor, the replacement parts and the accessories must be stored under the following
environmental conditions.
• In a dark place under the normal temperature atmospheric pressure and humidity away from direct
sunlight• In a place where gases, solvents, vapors, etc. are not present
Store the gas monitor in a shipping carton, if any, in which the product was delivered.
Store the gas monitor away from dust, etc. if the shipping carton is not available.
Please be aware of the direction at the time of storage.

CAUTION If the gas monitor is not used for a long time, turn on the power at least once every six months
and check that the pump draws in air (about three minutes). The gas monitor, when not activatedfor a long time, may cease to work because of hardening of the grease in the pump motor.

NOTE If the gas monitor with the lithium ion battery unit attached is not used for a long time, it isrecommended to store it after discharging the batteries until the battery level icon shows one battery
mark or so. If the gas monitor is stored with the batteries fully charged, the batteries get deteriorated
more quickly and may have shorter life.

9-2. Procedures to use the gas monitor again
When using the gas monitor after storage, perform calibration.

CAUTION
 Contact RIKEN KEIKI for readjustment including calibration.
 If there is a sudden temperature change of 15ºC or more between the storage and operational
locations, turn on the power of the gas monitor, let it stand for about 10 minutes in a similar
environment to the operational location, and perform air calibration in fresh air before using it.

- 69 -

9. Storage and disposal

9-3. Disposal of products
When the gas monitor is disposed of, it must be treated properly as an industrial waste in accordance withthe local regulations.

WARNING Do not disassemble the carbon monoxide, hydrogen sulfide or oxygen sensor because it
contains electrolyte. Electrolyte may cause severe skin burns if it contacts skin, while it may
cause blindness if it contacts eyes. If electrolyte is adhered on your clothes, that part on yourclothes is discolored or its material is decomposed.
If contact occurs, rinse the area immediately with a large quantity of water. Dispose of batteriesin accordance with procedure specified by the local authority.

<Disposal in EU Member States>
When disposing of the gas monitor in EU member states, sort the batteries as specified.
Handle the batteries removed from the lithium ion battery unit (BUL-8000) according to the classified
refuse collection system and recycling system based on the regulations of EU member states.
<Removing battery of lithium ion battery unit>
Remove the lithium ion battery unit with reference to "Charging the lithium ion battery unit (BUL-8000)" (P.
24).

NOTE
Crossed-out recycle dustbin mark
 This symbol mark is indicated on the products which contain the batteries
which fall under EU Battery Directive 2006/66/EC. Such batteries need tobe disposed of as specified by the latest Directive. This symbol markindicates that the batteries need to be separated from the ordinary waste
and disposed of appropriately.

- 70 -

10. Troubleshooting

10-1. Abnormalities on unit

10
10.

Troubleshooting

The troubleshooting does not explain the causes of all the malfunctions which may occur on the gas
monitor. This simply helps to find the causes of malfunctions which may frequently occur.
If the gas monitor shows a symptom which is not explained in this manual, or still has malfunctions eventhough remedial actions are taken, please contact RIKEN KEIKI.

10-1. Abnormalities on unit
Symptoms

CausesActions

The battery level is too low.

Lithium ion battery unit: Charge in a safe
place.

The POWER button was
released quickly.

For power-on, keep the POWER buttonpressed until a blip is heard.

Improper installation of thebattery unit

Check whether the battery unit is properlyattached to the main unit.

Abnormal operations

Disturbances by sudden
static electricity noise, etc.

Turn off the power once and then turn it on
again (restart).

Cannot operate the gas
monitor.

Disturbances by sudden
static electricity noise, etc.

Remove the battery unit in a safe place.
Then reinstall it and turn on the power toperform operations.

System abnormalities
FAIL SYSTEM

A circuit abnormality
occurred.

Please contact RIKEN KEIKI for repair.

Sensor abnormalities
FAIL SENSOR

A sensor has failed.

Please contact RIKEN KEIKI to replace
the sensor.(If "FAIL" is displayed in placeof measured value at power-on, the alarm
can be reset by pressing the ESC button.
The operation can be continued using only
the normal sensors to detect other gases.)

A low battery voltage
alarm is displayed.
FAIL BATTERY

The battery level is low.

The power cannot be
turned on.

- 71 -

Lithium ion battery unit: Turn off the powerand charge it in a safe place.

10. Troubleshooting
A low flow rate alarm isdisplayed.
FAIL LOW FLOW

Air calibration
impossible
FAIL AIR CAL

Clock abnormalities
FAIL CLOCK

The batteries cannot becharged.
(Lithium ion battery unit
only)

10-1. Abnormalities on unit
Water, oil or the like isdrawn.

Check the gas sampling hose for any
damage or mark of drawn water, oil, etc.

The gas sampling hose isclogged.

Check the gas sampling hose forconnections, clogging, twisting, etc.

The gas monitor was
powered on at a lowtemperature or has notbeen used for a long time.

Cycle the power several times. The pump
may start operating.

The pump has deteriorated.

Please contact RIKEN KEIKI to replace
the pump.

Fresh air is not suppliedaround the gas monitor.

Draw fresh air properly and perform air
calibration again. (P. 36)

A sensor has failed.

Please contact RIKEN KEIKI for repair.

Abnormalities of theinternal clock

Make a setting of date/time.
If a symptom like this is observed
repeatedly, the built-in clock is seemingly
malfunctioning. Thus, it must be replaced.
Please contact RIKEN KEIKI.

The charger is notconnected properly.

Connect the AC plug and DC plug of theAC adapter properly.

A charging circuit
abnormality occurred.

Please contact RIKEN KEIKI for repair..

The batteries have been
fully charged.

When fully charged batteries are charged
again, the charging indicator lamp does
not go on.

- 72 -

10. Troubleshooting

10-2. Abnormalities of readings

10-2. Abnormalities of readings
Symptoms
The reading rises(drops) and it remainsso.

Slow response

Span adjustment
impossible

CausesActions

Drifting of sensor output

Perform the air calibration. (P. 36)

Presence of interferencegas

Disturbances by interference gases, suchas solvents, cannot be eliminatedcompletely. Contact RIKEN KEIKI for
measures to take, such as a use ofremoval filter.

Slow leakA very small amount of the gas to bemeasured may be leaking (slow leak).
Because ignoring it may cause dangers,
take actions and measures which aretaken at an occurrence of gas alarm.

Environmental changes

Perform the air calibration. (P. 36)
In particular, the oxygen sensor is affectedby the air pressure.

Clogged dust filter

Replace the dust filter. (P. 66)

Bended or clogged gas
sampling hose

Fix the defective parts.

Condensation is formed
inside the gas monitor.

Fix the defective parts.

Deteriorated sensor
sensitivity

Please contact RIKEN KEIKI to replace
the sensor.

Improper calibration gas
concentration

Use the proper calibration gas.

Deteriorated sensor
sensitivity

Please contact RIKEN KEIKI to replace
the sensor.

- 73 -

11. Product specifications

11-1. RX-8500 specifications

11
11.

Product specifications

11-1. RX-8500 specifications
11-1-1. List of RX-8500 specifications

Measuring gas

Combustible gas(CH4)※1

Oxygen(O2)

Carbon monoxide(CO)

Carbon dioxide(CO2)

Measuring
principle

Non-dispersive
infrared type

Galvanic cell type

Electrochemical
type

Non-dispersive
infrared typeMeasuring range<Service range>

0 - 100.0% LEL/
4.5 - 100.0 vol%0 - 25.0 vol%<25.1 - 40.0 vol%>0 - 1000 ppm

0 - 20.0 vol%Minimum
resolution

0.5% LEL(0 - 100.0% LEL)
0.5 vol%(4.5 - 100.0 vol%)1ppm

0.01 vol%(0 - 2.00 vol%)0.05 vol%(2.00 - 5.00 vol%)0.1 vol%(5.00 - 20.0 vol%)Concentration
display
Sampling method
Suction flow rate
Displays
Buzzer soundvolumeGas alarm display
Gas alarm patternFault alarm/self
diagnosis
Fault alarm display
Fault alarm pattern
Transmission
methodFunctionsPower supply
Continuous
operating time
Operatingtemperatures
Operatinghumidities
Structure
Explosion-proof

0.1vol%LCD digital (7-segment + Symbol + Bar meter)
Sample-drawing
0.75 L/min or more (Open flow rate)
Battery level icon, pilot indicator, and pump operation status indicator
95 dB (A) or higher (30 cm)
Lamp blinking, intermittent buzzer sounding, and detail display
Self-latching
Low flow rate, battery voltage abnormalities, calibration failure, sensor abnormalities,
system abnormalities and clock abnormalities.
Lamp blinking, intermittent buzzer sounding, and detail display
Self-latching
IrDA (for data logger)
LCD backlight, peak display, pump stop, data logger and log data display
Dedicated lithium ion battery unit [BUL-8000(Z1)]
BUL-8000 [BUL-8000(Z1)]: About 15 hours (25°C, no alarm, no lighting and battery
fully charged)-20 - +50ºC
Below 95% RH (Non-condensing)Drip-proof and dust-proof performances (compliant to IP67 level)
Intrinsically safe explosion-proof structure- 74 -

11. Product specifications

11-1. RX-8500 specifications

Use pressure
80~110kPa
range
Response time
90% response within 20 seconds (at 20 ± 2 ℃)
25 seconds
Warm time
Explosion-proof
II1G Ex ia IIC T4 Ga（ATEX/UKEX）/ Ex ia IIC T4 Ga（IECEx）
class
Approx. 154 (W) x 81 (H) x 163 (D) mm (projection portions excluded)
Dimensions
About 1.2 kg (with BUL-8000(Z1)) <Standard>
Weight*1 When detecting other flammable gases, use the correction coefficient table in the appendix and replace
the display.
List of gases to be detected (EN standard compliant specification)
Applicablestandards

EN60079-29-1

EN50104

Detection
target gas

Methane

OxygenGas symbol

CH4

O2

Detection
range

0-100%LEL*1

4.5-100Vol%

0~25.0Vol%<25.1~40.0Vol%>

Alarm
setpoint

10-60%LEL

18.0~19.5Vol%
23.5~25.0Vol%

OperatingTemperature
range-20℃～50℃-20℃～50℃

Indication
accuracy±5% F.S Within±2.5% F.S Within<±12.0% F.S Within>※2

Repeatability±2% F.S Within±1% F.S Within※2

When instructions are rising
T50 less than 20s
T90 less than 60s

When instructions are rising
T20 less than 10s※2
T90 less than 45s※2

When the instruction is descending
T50 less than 20s
T10 less than 60s

When the instruction is descending
T20 less than 10s※2
T10 less than 45s※2

response

Calibration
Gas
concentration
Operatingrange
pressure

3.17~3.87Vol%

75~85Vol%N2Gas（99.9Vol%以上）

80~110kPa※3（No sudden change）
If there is a sudden pressure fluctuation, Low Flow alarm may be issued.

*1 The numerical definition of LEL is based on H600R-20-120XX.
*2 At constant ± 2 ℃ in the range of 15 - 25℃. Response time will tend to be longer if the temperature is lower than
this range.
*3 In the EN certification, tests are conducted at 「80 to 120 kPa」, but 「80 to 110 kPa」 because it is 「80 to 110 kPa」
ｆor explosion protection.

- 75 -

11. Product specifications

11-1. RX-8500 specifications

11-1-2. RX-8500 standard accessories
•
•
•
•
•
•
•
•
•

Lithium ion battery unit (BUL-8000)
AC adapter for charging
Gas sampling probe and gas sampling hose
Filter tube (CF-8385)
Relay tube
Absorbing tube fixing belt
Shoulder strap
CO2 removal filter
CO2 filter fixing belt

- 76 -: 1 pc (attached to main unit): 1 pc: 1 pc: 1 pc: 1 pc: 2 pcs: 1 pc: 1 pc: 1 pc11. Product specifications

11-2. RX-8700 specifications

11-2. RX-8700 specifications
11-2-1. List of RX-8700 specifications

Measuring gas
Measuring
principle

Combustible gas*1(HC)

Oxygen(O2)Hydrogen sulfide(H2S)

Non-dispersive
infrared type

Galvanic cell type

Electrochemical typeMeasuring range<Service range>

0 - 100.0% LEL/
1.5 - 100.0 vol%0 - 25.0 vol%<25.1 - 40.0 vol%>[Low
concentration]
0 - 30.0 ppm<30.5 - 100.0ppm>

Minimum
resolution

0.5% LEL(0 - 100.0% LEL)
0.5 vol%(1.5 - 100.0 vol%)0.1vol%0.5ppmConcentration
display

LCD digital (7-segment + Symbol + Bar meter)

Sampling method

Sample-drawing

Suction flow rate

0.75 L/min or more (Open flow rate)

Displays

Battery level icon, pilot indicator, and pump operation status indicator

Buzzer soundvolume95 dB (A) or higher (30 cm)

Gas alarm display

Lamp blinking, intermittent buzzer sounding, and detail display

Gas alarm pattern

Self-latching

Fault alarm/self
diagnosis

Low flow rate, battery voltage abnormalities, calibration failure, sensor abnormalities,
system abnormalities and clock abnormalities.

Fault alarm display

Lamp blinking, intermittent buzzer sounding, and detail display

Fault alarm pattern

Self-latchingTransmission
methodIrDA (for data logger)

Functions

LCD backlight, peak display, pump stop, data logger and log data display

Power supply

Dedicated lithium ion battery unit [BUL-8000(Z1)]

Continuous
operating time
Operatingtemperatures
Operatinghumidities

BUL-8000 [BUL-8000(Z1)]: About 15 hours (25°C, no alarm, no lighting and battery
fully charged)

Structure

Drip-proof and dust-proof performances (compliant to IP67 level)

Explosion-proof
structure
Explosion-proof
class

[High
concentration]
0 - 1000 ppm

1ppm-20 - +50ºC
Below 95% RH (Non-condensing)

Intrinsically safe explosion-proof structure
II1G Ex ia IIC T4 Ga（ATEX/UKEX）/ Ex ia IIC T4 Ga（IECEx）

Dimensions

Approx. 154 (W) x 81 (H) x 163 (D) mm (projection portions excluded)

WeightAbout 1.3kg (with BUL-8000(Z1)) <Standard>*1 The combustible gas HC concentration is displayed in isobutane conversion.
- 77 -

11. Product specifications

11-2. RX-8700 specifications

List of gases to be detected (EN standard compliant specification)
Applicablestandards

EN60079-29-1

EN50104

Detection
target gas

Isobutane

OxygenGas symbol

i-C4H10O2

Detection
range

0-100%LEL*1

0~25.0Vol%<25.1~40.0Vol%>

1.5-100Vol%

Alarm
setpoint

10-60%LEL

18.0~19.5Vol%
23.5~25.0Vol%

OperatingTemperature
range-20℃～50℃-20℃～50℃

Indication
accuracy±5% F.S Within±2.5% F.S Within<±12.0% F.S Within>※2

Repeatability±2% F.S Within±1% F.S Within※2

When instructions are rising
T50 less than 20s
T90 less than 60s

When instructions are rising
T50 less than 20s
T90 less than 60s

When the instruction is descending
T50 less than 20s
T10 less than 60s

When the instruction is descending
T50 less than 20s
T10 less than 60s

response

Calibration
Gas
concentration
Operatingrange
pressure

0.94-1.14Vol%

75-85Vol%N2Gas（99.9Vol%以上）

80~110kPa※3（No sudden change）
If there is a sudden pressure fluctuation, Low Flow alarm may be issued.

*1 The numerical definition of LEL is based on H600R-20-120XX.
*2 At constant ± 2 ℃ in the range of 15 - 25℃. Response time will tend to be longer if the temperature is lower than
this range.
*3 In the EN certification, tests are conducted at 「80 to 120 kPa」, but 「80 to 110 kPa」 because it is 「80 to 110 kPa」
ｆor explosion protection.

11-2-2. RX-8700 standard accessories
•
•
•
•
•
•
•

Lithium ion battery unit (BUL-8000(Z1))
AC adapter for charging
Gas sampling probe and gas sampling hose
Filter tube (CF-8385)
Relay tube
Absorbing tube fixing belt
Shoulder strap- 78 -: 1 pc (attached to main unit): 1 pc: 1 pc: 1 pc: 1 pc: 2 pcs: 1 pc11. Product specifications

11-3. List of optional items

11-3. List of optional items
Waist strap
Waist strap fixing tool
Protection film
Protection film (5 pcs)
Lithium ion battery unit (BUL-8000)
AC adapter
AC adapter replacement plug
AA alkaline battery (TOSHIBA)
Absorbent cotton (for CF-8385)
Dust filter (10 pcs) (for CF-8385)
Dust filter (10 pcs) (for gas sampling probe)
Data logger management program
Demand flow valve
Trap filter
Sampling hose with weight (30 m)
Sampling hose with float (30 m)
Aluminum trunk case (RoHS compliant)Aluminum trunk case (non RoHS compliant)
Shipboard storage box (metal, RoHS compliant)Set of gas sampling bags
Calibration gas can (0.6 L N2: 99.99% or more)
Calibration gas can (0.6 L i-C4H10: 50% LEL, Air: balance)
Calibration gas can (0.6 L i-C4H10: 10%, N2: balance)
Calibration gas can (0.6 L CH4: 70% LEL, N2: balance)
Calibration gas can (0.6 L CH4: 70%, N2: balance)
Calibration gas can (0.6 L CO2: 10%, N2: balance)
Calibration gas can (0.6 L CO: 145 ±5 ppm, N2: balance)
Hydrogen sulfide calibration gas kit (CK-82)

CAUTIONBe sure to use the sampling hose with weight (30 m) in combination with the filter tube (CF8385) for dust removal and water-proof performance.
If water, etc. is drawn while the filter tube is unattached, it enters the inside of the unit andcauses a trouble.

- 79 -

12. Appendix

12-1. Definition of terms

1212.

Appendix12-1. Definition of termsvol%Gas concentration indicated in the unit of one-hundredth of the volumeppm

Gas concentration indicated in the unit of one-millionth of the volume

LEL

The acronym of Lower Explosive Limit.
LEL refers to the lowest concentration of a combustible gas in air capable ofcausing explosion when ignited.

Self-latching

One of alarm patterns. Once an alarm is triggered, this keeps the alarm activateduntil it is reset even when the alarm conditions are not met.

12-2. Calibration history/various trend/event history
functions
The gas monitor has history and trend functions. To use this function, please contact RIKEN KEIKI.

NOTE

 The data logger management program (optional) is required to use the history and trend functions.
Contact RIKEN KEIKI for more information.

Data logger provides five functions.

(1) Interval trend
Records the change of measured concentration from power-on to power-off.
Up to 100 latest data are recorded.
After the number of recorded data reaches 100, the oldest data will be overwritten by the latest data.
* However, when the maximum recording time is exceeded, the oldest data will be deleted before reaching
100.
The maximum recording time is specified as follows for each interval time.
1020301-minute 3-minuteInterval time
secondsecondsecond180
Maximum
10 hours 20 hours 30 hours 60 hours
hours
recording time
* The standard interval time is "5 minutes."
Interval time can be set by "Data Logger Management Program" (optional).

- 80 -

5-minute
300
hours

10minute
600
hours

12. Appendix

12-2. Calibration history/various trend/event history functions(2) Alarm trend
Starting immediately after the alarm is triggered, this function records the change of measured
concentration for one hour, which is from 30 minutes before the alarm was triggered until 30 minutes after
the alarm was triggered.
Alarm trend records the peak value of five-second time at a 5-second interval.
Last eight measurement data shall be recorded.
When the number of data exceeds eight, the oldest data will be overwritten by the latest data.

(3) Alarm event
Records the trigger of alarm as an event.
The event records the time of alarm trigger, target measuring gas and type of alarm event (full scale, firstor second alarm setpoint).
Up to 100 latest events are recorded.
After the number of recorded events reaches 100, the oldest data will be overwritten by the latest data.

(4) Trouble event
Records the trigger of fault alarm as an event.
The event records the time when the trouble was triggered, the target gas of measurement, and the typeof fault event.
Up to 100 latest events are recorded.
After the number of recorded events reaches 100, the oldest data will be overwritten by the latest data.

(5) Calibration history
Records data when the calibration is performed.
The history records the calibration time, concentration values before and after the calibration, as well as
the calibration error.
Up to 100 latest calibration data are recorded.
After the number of recorded data reaches 100, the oldest data will be overwritten by the latest data.

NOTE The data logger function of this gas monitor is entirely based on the overwriting system (the oldest
data is deleted and the latest data is recorded).
 The recorded data can be read out by the "Data Logger Management Program" (optional). See theoperating manual of "Data Logger Management Program" for more information.

- 81 -

12. Appendix

Revision or Abolition History

Revision or Abolition History
Edition

RevisionIssue date

0First issue

2020/7/1

1

User mode added

2020/9/29

2

Declaration of Conformity

2020/10/23

3

Safety Information, Declaration of Conformity

2021/10/29

4

Safety Information, Declaration of Conformity

2022/11/24- 82 -

12. Appendix

Revision or Abolition History- 83 -

12. Appendix

Revision or Abolition History- 84 -